Welcome to the forum
https://www.keystonerv.com/solarflex-200-overview
Looks like the inverter will power up to 7 outlets. If you have a Romex “loop”, that’s where the inverter gets installed. Your inverter should have AC in, AC OUT and DC IN.
The AC IN will be the Romex that is energized by shore/gen power.
The AC OUT will be the Romex going to the outlets
The DC IN is the cables from the battery(s) to power the inverter. Make sure you size the cables depending on distance from battery(s).
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