How do my friends join my Unturned server?

Unturned gives every server a numeric Server Code, and it is the easiest way to get people in. When your server starts, the Console prints a line reading Server Code: <digits> followed by a note that your friends can enter that code in the Connect Directly menu to join without port forwarding. Copy the digits and send them over.

Your friends open Unturned, choose Play, then Connect Directly, and enter the code. There is no address to type, no port to explain, and nothing for them to forward.

You can also join by address if you prefer. Your server address and port are on the Network page in the panel. Give players both, and they connect the way they would to any other dedicated server.

By default your server will not appear in the public Steam server list. Appearing there needs a Game Server Login Token, which you add as -GSLT <token> under Additional Arguments on the Startup page. You generate that token yourself from Steam's Game Server Account Management page using App ID 1110390. This is optional: players can always join by Server Code or by address without it.

If you want the server private, add -Password <yourpassword> to Additional Arguments and share the password alongside the code.