Install the SDL3 development library (sudo dnf install SDL3-devel on fedora, for example) and run ./run.sh to compile (gcc) and run.
Download the VC version of SDL3-devel, rename the the SDL3-version_number (e.g. SDL3-3.2.16) folder that's inside it to SDL3-win, and then copy SDL3-win to gameboy_emu. Run run.bat to compile (MSVC) and run.