The server I was using to host the lobby and do the relay must be down and I can’t get it back running.
Unity bought the multiplayer package I was using to make the game and they changed it so much I’ll practically have to start the game from scratch again if I want to modify it and fix the lobbies.
I’ll be working on a new version later this year but for now there’s not much to do.
It's using Photon's Realtime relay server. Just share the room ID (click to copy) and your friends should be able to connect. If this doesn't work for you, let me know, I've been trying to fix all the bugs related to the connection.
