I'll add a bit here for absolute beginners wanting to bridge to Bluesky – you'll see the address for following bridged users is shown as "@ username.app.tld.ap.brid.gy" – a real world example would be to substitute "mastodon.social" for the "app.tld" section. So in my case "@ andyrush.mastodon.social.ap.brid.gy" (I puposely left spaces after the @ so my Mastodon app wouldn't auto-complete).