I looked at the wiki (The world's most empty wiki...), clicked the link and read the page, it did not help that much. It's even a year old and was made for REI 5, which is outdated. (I think)

so how do you make plugins for this?

P.S: Act like I am a beginner at making Minecraft mods because I am!! (only watch a few tutorials for fabric)

i dont think this issue is technical enough for github, maybe ask this in the discord?