Can't find fltk library with cmake (ERROR)

I am not able to link fltk library using cmake script.Here is my CMakeLists.txt file:

cmake_minimum_required(VERSION 3.16.5)
SET(CMake_C_Compiler_Works 1)
SET(CMake_CXX_Compiler_Works 1)
 project(Windows)
find_package( REQUIRED NO_MODULE)
SET(src ./Hello_Windows.cpp)
add_executable(win ${src})
 target_link_libraries(win fltk)

But cmake is reporting that it is unable to locate fltk file and reports error
cmake Error at CMakeLists.txt:7 (find_package):
Could not find a package configuration file provided by “FLTK” with any of
the following names:

FLTKConfig.cmake
fltk-config.cmake

Add the installation prefix of "FLTK" to CMAKE_PREFIX_PATH or set
" FLTK_DIR" to a directory containing one of the above files.  If "FLTK"
provides a separate development package or SDK, be sure it has been
installed.


  -- Configuring incomplete, errors occurred!
See also "D:/C++_project/build/CMakeFiles/CMakeOutput.log".

I have installed my fltk library with pacman on MSYS2

Why are you manually setting these?

3.17 has --debug-find which can help you see where CMake is looking. I suspect that FLTK is installing its configuration to the wrong place or that it doesn’t have one. If the latter, you’ll probably do better by removing the NO_MODULE so that the FindFLTK.cmake that CMake ships can be used.

Yeah,sorry for that I was using that flag when I was trying to resolve an error.Let me try.