I guess the 2018 Raptor is different?? My Raptor doesn't have a plug like this on the back of the mirror. It has a couple of large plastic covers that need to be removed to get access to the wiring for the mirror. There are a couple of plugs under there and many wires.. just don't want to have to try to test every one of them to located a keyed hot and ground wire if possible. :/
IIRC from reading f150 forums some trucks have a cover over the back but the same plug and wiring inside. The cover is removed to access the wiring.