- or how to get hold of a runnable executable.
For a quick solution, see if you can use a pre-built binary (look in Pre-built executable binaries)
If your know your way around target and/or cross compiling, you will probably know how to proceed: simply use the CMake build.
For cross-compile setup, take a look the raspi4-32.cmake file in the root folder of the project. The script file build.sh in the same spot shows how I build pi-fan myself.