An invite is a single-use code an admin hands you. Redeeming it connects your client to their server and starts following the channels your groups are assigned.
Open the client and, on the Welcome tab, choose Join with invite…. Paste the server URL and the invite code, and pick where builds should be installed. That’s it — the client connects and starts following the channels you were granted.
Same effect, scriptable:
nightship join https://builds.example.com <code> --install-root <path>This connects your client and starts following the channels your groups are assigned, downloading each channel’s current build.
If you know the server’s URL, ask for access from the app: Add server, enter the URL, then Request access… with your preferred user name and your email. The admin approves it and the invite arrives by mail; then join as above.
Locked out of your own server, with no admin left to approve? See Lost access to your server.