Cannot find "SDL_ttf.h" even though Cmake ran fine

So I took the FindSDL2TTF.cmake, and replaced the path corresponding to my SDL2_ttf-2.0.14 files (I use Development Libraries for MinGW 32/64-bit).

My CMakeList.txt looks like this:

cmake_minimum_required(VERSION 3.9)
project(MY_PROJECT)

set(CMAKE_C_STANDARD 99)
set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${PROJECT_SOURCE_DIR}/Cmake")
find_package(SDL2 REQUIRED)
find_package(SDL2_IMAGE REQUIRED)
#find_package(SDL2_MIXER REQUIRED)
Find_Package (SDL2TTF REQUIRED)

include_directories( ${SDL2_INCLUDE_DIR} )

add_executable(MY_PROJECT main.c )

include_directories(${SDL2_INCLUDE_DIR}
 ${SDL2_IMAGE_INCLUDE_DIR}
 ${SDL2_MIXER_INCLUDE_DIR}
 ${SDL2TFF_LIBRARY}
 )
target_link_libraries(MY_PROJECT ${SDL2_LIBRARY}
 ${SDL2_IMAGE_LIBRARY}
 ${SDL2_MIXER_LIBRARY}
 ${SDL2TFF_LIBRARY}
 )

And I have loaded the Cmake file successfully, no error whatsover. I can run and build my project also.
However, if I include my SDL_tff.h library, Clion just cannot find it, making it impossible to use the library.

Any idea what could be the cause, and some solutions?

Thanks