I typed "RV side Hatch" into Amazon and it came up and about 10 others sizes.

https://www.amazon.com/Swess-Trailer-Electric-Power-Compatible/dp/B08HVK6ZC2/ref=sr_1_15?crid=T3DLH7V8PRY8&keywords=rv+side+hatch&qid=1661894529&sprefix=rv+side+hatch%2Caps%2C116&sr=8-15

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They are also calling it a "RV Cable Hatch".