"Installing" a Discord server "on a wiki" is done via one of several scripts from the dev wiki. With the recent enabling of JS review for UCP you could try to import one of them. However, there is a possibility that they won't work. The reason this may be the case is that they are written for the legacy platform and search for things on the page assuming the legacy platform's layout. The UCP layout is significantly different.
That wording is from FANDOM staff... why are you asking here?
Also it turns out the JS Review being enabled today was a slight false alarm as in it may work, but only probably FANDOM staff can actually edit JS pages right now as some user rights thing changed. See Thread:1929836#23.
Well, when I first started writing it I didn't have the quoted part. I really do wish I understood FANDOM's engineering process, because then I might be more sympathetic to what seems to be pretty far below industry standard... at least Silicon Valley standards.