Use kotlin coroutines.

Installed last version of InteliJ Community Version. Created a project with coroutines example from jetbrains WEB site.

"

/*
 * Copyright 2016-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
 */

// This file was automatically generated from coroutines-basics.md by Knit tool. Do not edit.
package kotlinx.coroutines.guide.exampleBasic01

import kotlinx.coroutines.*

fun main() = runBlocking { // this: CoroutineScope
    launch { // launch a new coroutine and continue
        delay(1000L) // non-blocking delay for 1 second (default time unit is ms)
        println("World!") // print after delay
    }
    println("Hello") // main coroutine continues while a previous one is delayed
}

When building I get:

"e: C:\Users\Stephan\IdeaProjects\Lab2\src\main\kotlin\Main.kt: (1, 8): Unresolved reference: kotlinx"

How can be fixed?