Stop server, wait 5min, browse thorough the file manager and add your SteamUID. Save, restart.
If file does not exist, create one on your PC using notepad. Add SteamUID, save, then upload through filemanager. Restart server.
Once ingame use ` to access the console. Type in "list". You should have about 60 commands that list. That alone shows you are logged in.
Not all commands will work. That has something to do with the game. You can test with the kill command.
If it still does not work, feel free to contact Nitrado Support by submitting a ticket.
Thank you very much for the reply - I will try this tonight when I am off work.