we have to display "gameover" at the end of the code, help me to do it ASAP, please!

import random  # For generating random numbers
import sys  # We will use sys.exit to exit the program
import pygame
from pygame.locals import *  # Basic pygame imports

# Global Variables for the game
FPS = 32   #32
SCREENWIDTH =  289  #289
SCREENHEIGHT = 511    #511
SCREEN = pygame.display.set_mode((SCREENWIDTH, SCREENHEIGHT))
GROUNDY = SCREENHEIGHT * 0.8    #0.8
GAME_SPRITES = {}
GAME_SOUNDS = {}
PLAYER = 'gallery/sprites/bird.png'
BACKGROUND = 'gallery/sprites/background.png'
PIPE = 'gallery/sprites/pipe.png'


def welcomeScreen():
    """
    Shows welcome images on the screen
    """

    playerx = int(SCREENWIDTH / 5)
    playery = int((SCREENHEIGHT - GAME_SPRITES['player'].get_height()) / 5)
    messagex = int((SCREENWIDTH - GAME_SPRITES['message'].get_width()) / 2)
    messagey = int(SCREENHEIGHT * 0.13)
    basex = 0
    while True:
        for event in pygame.event.get():
            # if user clicks on cross button, close the game
            if event.type == QUIT or (event.type == KEYDOWN and event.key == K_ESCAPE):
                pygame.quit()
                sys.exit()

            # If the user presses space or up key, start the game for them
            elif event.type == KEYDOWN and (event.key == K_SPACE or event.key == K_UP):
                return
            else:
                SCREEN.blit(GAME_SPRITES['background'], (0, 0))
                SCREEN.blit(GAME_SPRITES['player'], (playerx, playery))
                SCREEN.blit(GAME_SPRITES['message'], (messagex, messagey))
                SCREEN.blit(GAME_SPRITES['base'], (basex, GROUNDY))
                pygame.display.update()
                FPSCLOCK.tick(FPS)


def mainGame():
    score = 0
    playerx = int(SCREENWIDTH / 5)
    playery = int(SCREENWIDTH / 2)
    basex = 0

    # Create 2 pipes for blitting on the screen
    newPipe1 = getRandomPipe()
    newPipe2 = getRandomPipe()

    # my List of upper pipes
    upperPipes = [
        {'x': SCREENWIDTH + 200, 'y': newPipe1[0]['y']},
        {'x': SCREENWIDTH + 200 + (SCREENWIDTH / 2), 'y': newPipe2[0]['y']},
    ]
    # my List of lower pipes
    lowerPipes = [
        {'x': SCREENWIDTH + 200, 'y': newPipe1[1]['y']},
        {'x': SCREENWIDTH + 200 + (SCREENWIDTH / 2), 'y': newPipe2[1]['y']},
    ]

    pipeVelX = -4

    playerVelY = -9
    playerMaxVelY = 10
    playerMinVelY = -8
    playerAccY = 1

    playerFlapAccv = -8  # velocity while flapping
    playerFlapped = False  # It is true only when the bird is flapping

    while True:
        for event in pygame.event.get():
            if event.type == QUIT or (event.type == KEYDOWN and event.key == K_ESCAPE):
                pygame.quit()
                sys.exit()
            if event.type == KEYDOWN and (event.key == K_SPACE or event.key == K_UP):
                if playery > 0:
                    playerVelY = playerFlapAccv
                    playerFlapped = True
                    GAME_SOUNDS['wing'].play()

        crashTest = isCollide(playerx, playery, upperPipes,
                              lowerPipes)  # This function will return true if the player is crashed
        if crashTest:
            return

            # check for score
        playerMidPos = playerx + GAME_SPRITES['player'].get_width() / 2
        for pipe in upperPipes:
            pipeMidPos = pipe['x'] + GAME_SPRITES['pipe'][0].get_width() / 2
            if pipeMidPos <= playerMidPos < pipeMidPos + 4:
                score += 1
                print(f"Your score is {score}")
                GAME_SOUNDS['point'].play()

        if playerVelY < playerMaxVelY and not playerFlapped:
            playerVelY += playerAccY

        if playerFlapped:
            playerFlapped = False
        playerHeight = GAME_SPRITES['player'].get_height()
        playery = playery + min(playerVelY, GROUNDY - playery - playerHeight)

        # move pipes to the left
        for upperPipe, lowerPipe in zip(upperPipes, lowerPipes):
            upperPipe['x'] += pipeVelX
            lowerPipe['x'] += pipeVelX

        # Add a new pipe when the first is about to cross the leftmost part of the screen
        if 0 < upperPipes[0]['x'] < 5:
            newpipe = getRandomPipe()
            upperPipes.append(newpipe[0])
            lowerPipes.append(newpipe[1])

        # if the pipe is out of the screen, remove it
        if upperPipes[0]['x'] < -GAME_SPRITES['pipe'][0].get_width():
            upperPipes.pop(0)
            lowerPipes.pop(0)

        # Lets blit our sprites now
        SCREEN.blit(GAME_SPRITES['background'], (0, 0))
        for upperPipe, lowerPipe in zip(upperPipes, lowerPipes):
            SCREEN.blit(GAME_SPRITES['pipe'][0], (upperPipe['x'], upperPipe['y']))
            SCREEN.blit(GAME_SPRITES['pipe'][1], (lowerPipe['x'], lowerPipe['y']))

        SCREEN.blit(GAME_SPRITES['base'], (basex, GROUNDY))
        SCREEN.blit(GAME_SPRITES['player'], (playerx, playery))
        myDigits = [int(x) for x in list(str(score))]
        width = 0
        for digit in myDigits:
            width += GAME_SPRITES['numbers'][digit].get_width()
        Xoffset = (SCREENWIDTH - width) / 2

        for digit in myDigits:
            SCREEN.blit(GAME_SPRITES['numbers'][digit], (Xoffset, SCREENHEIGHT * 0.12))
            Xoffset += GAME_SPRITES['numbers'][digit].get_width()
        pygame.display.update()
        FPSCLOCK.tick(FPS)


def isCollide(playerx, playery, upperPipes, lowerPipes):
    if playery > GROUNDY - 25 or playery < 0:
        GAME_SOUNDS['hit'].play()
        return True

    for pipe in upperPipes:
        pipeHeight = GAME_SPRITES['pipe'][0].get_height()
        if (playery < pipeHeight + pipe['y'] and abs(playerx - pipe['x']) < GAME_SPRITES['pipe'][0].get_width()):
            GAME_SOUNDS['hit'].play()
            return True

    for pipe in lowerPipes:
        if (playery + GAME_SPRITES['player'].get_height() > pipe['y']) and abs(playerx - pipe['x']) < \
                GAME_SPRITES['pipe'][0].get_width():
            GAME_SOUNDS['hit'].play()
            return True

    return False


def getRandomPipe():
    """
    Generate positions of two pipes(one bottom straight and one top rotated ) for blitting on the screen
    """
    pipeHeight = GAME_SPRITES['pipe'][0].get_height()
    offset = SCREENHEIGHT / 3
    y2 = offset + random.randrange(0, int(SCREENHEIGHT - GAME_SPRITES['base'].get_height() - 1.2 * offset))
    pipeX = SCREENWIDTH + 10
    y1 = pipeHeight - y2 + offset
    pipe = [
        {'x': pipeX, 'y': -y1},  # upper Pipe
        {'x': pipeX, 'y': y2}  # lower Pipe
    ]
    return pipe


if __name__ == "__main__":
    # This will be the main point from where our game will start
    pygame.init()  # Initialize all pygame's modules
    FPSCLOCK = pygame.time.Clock()
    pygame.display.set_caption('Flappy Bird by Nishat & Alina')
    def GAMEOVER():
        """crashes the player down ans shows gameover image"""
        score = GAMEOVER['score']
        playerx = SCREENWIDTH * 0.2
        playery = GAMEOVER['y']
        playerHeight = GAME_SPRITES['player'][0].get_height()
        playerVelY = GAMEOVER['playerVelY']
        playerAccY = 2
        playerRot = GAMEOVER['playerRot']
        playerVelRot = 7

        basex = GAMEOVER['basex']

        upperPipes, lowerPipes = GAMEOVER['upperPipes'], GAMEOVER['lowerPipes']

        # play hit and die sounds
        GAME_SOUNDS['hit'].play()
        if not GAMEOVER['groundCrash']:
            GAME_SOUNDS['die'].play()

        while True:
            for event in pygame.event.get():
                if event.type == QUIT or (event.type == KEYDOWN and event.key == K_ESCAPE):
                    pygame.quit()
                    sys.exit()
                if event.type == KEYDOWN and (event.key == K_SPACE or event.key == K_UP):
                    if playery + playerHeight >= GROUNDY - 1:
                        return
                        # player y shift
                        if playery + playerHeight < GROUNDY - 1:
                            playery += min(playerVelY, GROUNDY - playery - playerHeight)

                        # player velocity change
                        if playerVelY < 15:
                            playerVelY += playerAccY

                        # rotate only when it's a pipe crash
                        if not GAMEOVER['groundCrash']:
                            if playerRot > -90:
                                playerRot -= playerVelRot

                        # draw sprites
                        SCREEN.blit(GAME_SPRITES['background'], (0, 0))

                        for uPipe, lPipe in zip(upperPipes, lowerPipes):
                            SCREEN.blit(GAME_SPRITES['pipe'][0], (uPipe['x'], uPipe['y']))
                            SCREEN.blit(GAME_SPRITES['pipe'][1], (lPipe['x'], lPipe['y']))

                        SCREEN.blit(GAME_SPRITES['base'], (basex, GROUNDY))
                        showScore(score)

                        playerSurface = pygame.transform.rotate(GAME_SPRITES['player'][1], playerRot)
                        SCREEN.blit(playerSurface, (playerx, playery))
                        SCREEN.blit(GAME_SPRITES['gameover'], (50, 180))

                        FPSCLOCK.tick(FPS)
                        pygame.display.update()
    GAME_SPRITES['numbers'] = (
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/0.png").convert_alpha(),
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/1.png").convert_alpha(),
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/2.png").convert_alpha(),
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/3.png").convert_alpha(),
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/4.png").convert_alpha(),
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/5.png").convert_alpha(),
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/6.png").convert_alpha(),
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/7.png").convert_alpha(),
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/8.png").convert_alpha(),
        pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/9.png").convert_alpha(),
    )
    GAME_SPRITES['message'] = pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Downloads/message.jpeg").convert_alpha()
    GAME_SPRITES['base'] = pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/base.png").convert_alpha()
    GAME_SPRITES['pipe'] = (pygame.transform.rotate(pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/pipe.png").convert_alpha(), 180),
                            pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/pipe.png").convert_alpha()
                            )
    GAME_SPRITES['GAMEOVER'] = pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Downloads/gameover.jpeg").convert_alpha()

    # Game sounds
    GAME_SOUNDS['die'] = pygame.mixer.Sound("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/audio/die.wav")
    GAME_SOUNDS['hit'] = pygame.mixer.Sound("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/audio/hit.wav")
    GAME_SOUNDS['point'] = pygame.mixer.Sound("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/audio/point (1).wav")
    GAME_SOUNDS['swoosh'] = pygame.mixer.Sound("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/audio/swoosh (1).wav")
    GAME_SOUNDS['wing'] = pygame.mixer.Sound("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/audio/wing (1).wav")

    GAME_SPRITES['background'] = pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/background.jpg").convert()
    GAME_SPRITES['player'] = pygame.image.load("C:/Users/nishat/Dropbox/My PC (DESKTOP-HKC17O3)/Desktop/flappy bird/sprites/bird1.png").convert_alpha()

    while True:
        welcomeScreen()  # Shows welcome screen to the user until he presses a button
        mainGame()  # This is the main game function