You seem to be misunderstanding the poster’s request.
He/she doesn’t want to add some home-baked bit of code to some geeky repository…
He/she wants to invoke the functionality of an already existing extension on his/her personal freeflarum!
You’ve got 200+ extensions listed on free flarum, extensions that provide all sorts of different functionality.
But how does a freeflarum site owner add that functionality to THEIR site? How do THEY install or make operational the extension(s)? How do THEY add the extension’s functionality to THEIR freeflarum?
Nowhere can I find any instructions on how to utilise an extension!
HELP!!!