Spaceships are self-charging. They do not need to be hooked up to a powered campsite. Therefore you can camp at cheap or free (unpowered) campsites. No power is needed, so there is no option to connect a power cable to your Spaceships campervans, there is no mains hook-up.

More info about the self-charging smart battery system of Spaceships

Your Spaceships campervan does not come with an electrical hook-up cord for powered campsites! All Spaceships are self-charging, no mains cord or electrical hook-up cord is needed.
You can camp at unpowered campsites.