"MapPlayerLocation": Confused about how and where to enter it.

I understand that entering

MapPlayerLocation = True

into the gameusersettings.ini file will allow a marker on the map that will give the player location. How do I enter that into the Nitrado server files? The "Engine Settings" page has a "Custom Game.ini Settings" field, but where to I enter a line for gameusersettings.ini?

I can also download settings as a .json file. Should I modify that?

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On the webUI, check it.

Check what exactly?

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It will show the marker of where you are at only to you. Its not for others.

But how do I make the marker appear?