The Isle Evrima uses RCON over TCP. In your server’s Game.ini, under [/Script/TheIsle.TheIsleGameSession], set:
RconEnabled=True
RconPort=8888
RconPassword=YourStrongPassword
Restart the server, and make sure the RCON port is open in your host’s firewall.
Then add the server in PanelForge using the server IP, that RCON port, and the password.