Frustratingly, your first link there works for me, but the other two return 404s...
It's possible your space isn't federated with those communities yet? You might need to start the link with searching for them using the !instance@web.site command to force your instance to download their pages first.
How do I get to those from your comment? I clicked them and it just opened Gmail and decided the links were the addresses lol.
in the search tool of your instance enter !risa@startrek.website and it will find it and start federating it.
Try this, I'm still learning how to link other communities. StarTrek - Mainsub Discussion Daystrom Institute - In Depth/In Universe Discussion Risa - Memes&Shitposting
Frustratingly, your first link there works for me, but the other two return 404s...
It's possible your space isn't federated with those communities yet? You might need to start the link with searching for them using the !instance@web.site command to force your instance to download their pages first.