It looks like the source is setup for 1.14 and vanilla only. I can't figure out how to build the fabric mod, even though there's a 1.16 version that seems to work.

Please use the correct branch name that targets fabric. Please note the current fabric release for 1.16.3 works fine with 1.16.4

Wow, I feel dumb. I didn't even think about different branches for some reason. I was able to build it and run it myself, thanks! I sent you a donation using the link on curseforge, hope you got it.