Not a PMK (plainmasterkey). Or at least, it is possible but it won't do you any good since the FreeCAM does not auto-update its internal keys. PMK is used for auto-update.
But it is possible to enter the lowest level, non auto-updating PKs (plainkeys) via the remote. That's what the "enter keys" function in the CAM's menu is for. They must however be entered as strings of decimal numbers (since only digits 0...9 are supported on a standard remote). So you need to convert the actual hexadecimal codes for provider and plainkey into decimal "freecam codes". That process has been discussed before on the board so you can get more detail by locating those older threads (search function).
2old