NOCO GCP1 15A AC Port Plug, 125V Power Inlet Socket, and Waterproof Electrical Outlet Receptacle Box with 16-Inch Integrated Outdoor Extension Cord

Buy one of these: https://a.co/d/032wvBzW And one of these: https://a.co/d/0hgutIcS The NOCO has ring terminals and is permanently installed to charge the batteries. The second item is the port adapter for shore power so you can quickly run an extension cord to shore power just make sure it’s a good quality wet weather rated cord and you should be good.

https://a.co/d/0dncMtP7 This is also something to consider, but may not jive well with an inspector if it's run inside of a wall.