Where to plug in trailer lights on a Lance 1181?

Good points and questions. The previous owner wired a pigtail and extension to the camper so that it could be plugged into the trucks 7-pin. As for plugging it in, the sellers showed me that when they were backing the truck up to the camper, they stopped about two feet short, plugged the camper into the rear bumper, then backed the truck the rest of the way then lowered the camper...