1. Login to the SanoServers Control Panel
  2. Navigate to your server’s control panel
  3. Stop your server if it’s running.
  4. Click Files on the left-hand side of the server’s control panel
  5. Navigate to /garrysmod/cfg/
  6. Double click on the server.cfg file
  7. Find the line that says sv_password ""
  8. Replace "" with your desired password
  9. Save the file
  10. Restart your server

Your Garrys Mod server should now be password protected. Players will now need to enter the password to join your server.