I don't know if they still use this little 20A transfer switch in the newer units, but this is what came with the 2000W inverter for switching those outlets between shore and inverted power. It was plugged into the inverter. You can probably trace circuits from here and add a small junction box to wire nut things into.
If you want to go nuts and have all the outlets on the inverter, you can do what I did here (2018 version).
https://www.montanaowners.com/forums...ad.php?t=75474
The new version has the two ACs added when I replaced the 2000W inverter with a 3000W hybrid a couple years ago.