Take a picture.Put in the domestic 311 only to find that the water inlet is off to the side and the water line is to short to reach.
Where does the water line come from? How hard is it to replace?
Or can is just right up a male female couple with a short piece of hose?
What is the hose diameter? The fitting looks like 3/4"
You likely have PEX piping which can be easily extended.
The screw on connector is likely 1/2" (don't get me started on plumbing fittings size "standards". Your Dometic installation instructions should tell you what the toilet needs.