Beginning in version 3.20.4.0 Unturned dedicated servers can be authenticated using a Game Server Login Token or GSLT. After version 3.21.31.0 anonymous servers (without GSLT) are hidden from the internet server list.
You can manually create GSLTs while logged in with your Steam account here: https://steamcommunity.com/dev/managegameservers
Use Unturned's app ID 304930, and a memo to remind you which server the token is for.
The GSLT can be set in one of two places depending on your preference:
- With the Login_Token property in each server's Config.json file under the Browser section.
- Using the GSLT command during startup. This can be specified in the Commands.dat file or on the command-line.
Please feel free to lodge a support ticket if you have any further questions.