Yeah I can't remember how I found the invite link before. It must have been in one of his videos. I tried to create an invite link but it must be disabled to only be students. I found this on his website though that should start your path a bit easier.
https://zerotomastery.io/community/developer-community-discord
Well I followed that link and it looks to promote just joining their academy. I didn't go that path so it must be included in the master course at some point. I'll keep you posted if I find an actual invite link.