I attempted to manually load this mod into Modrinth running on Fabric 1.21. I was able to add the shriekercounter-1.0.0.jar, as well as accompanying completeconfig and YetAnotherConfigLib mods into Modrinth (again using Fabric loader and the API already present).

Getting a crash on attempting to start the game.

Attached is the error log, which I reproduced with all other mods disabled.
shriekercounter minimal mods crashlog.txt