Nope, any browser should work. The compose file in my repo should be exposing qbittorrent on port 8080 (line 27 in the file). I would say first:

1. make sure the containers are running, use podman-compose ps or docker-compose ps from the folder that contains the compose file
2. use ping to make sure you can reach the server
3. use ss or netstat on your server to make sure it’s actually listening on the port you expect qBittorrent to be listening on (8080 unless you changed it)
4. view logs using podman-compose logs from the folder that contains the compose file
5. if you can see the web ui but don’t know what the password is, use podman-compose logs and you should see the temporary password generated by qBittorrent (this is explained in the guide)

This was mentioned in the other thread but I should probably mention it here as well. Unlike with TOR, in I2P every user is also expected to be a router. I think this is great and helps encourage decentralization, scaling, and DDoS resistance. Techlore mentioned something similar in one of his videos (but I can’t find it right now). However, this does mean that you never really know what traffic is going through your router. It’s all encrypted, but some users may still have concerns with that. I wrote my own opinions on this topic in that same comment thread.

There’s basically only one, listed towards the bottom of the guide in the repo: http://tracker2.postman.i2p/. And it’s “public” but only accessible via I2P. I tried to explain everything in the repo so let me know if I missed anything!