If you click HERE this will take you to our article on all four ways you can connect to your server via permissions
Make sure you STOP your server before proceeding.
In the control panel, go into your File Manager and follow the path:
ShooterGame and then go into Saved.
In Saved, you will need to click the tab that says New File and when it asks what you would like to name it, enter : AllowedCheaterSteamIDs.txt
The finished path should look like this after you create the new file: \ShooterGame\Saved\AllowedCheaterSteamIDs.txt
Now go into the AllowedCheaterSteamIDs.txt
There it will explain on how to retrieve the Steam64 ID(s) you need required for your list.
Save and start your server.