To keep your RV generator in top shape and to make sure the generator is running properly you should start the RV generator and run the generator under full load at least once per month for at least an hour or two.
That will make sure the generator will operate when you need it and you'll find out beforehand if something is wrong with the generator before setting out on a trip and then finding out then that the RV generator won't work.
So even if you have electric power you should start the RV generator at least once per month to keep the fuel flowing through the lines and to make sure it runs.
Letting the RV generator motor sit too long can cause problems with it and then it might not start up properly.
Even my portable generator I start it up twice per month and use it to run some tools even if I already have a power outlet nearby.
It's good to make sure the generator starts up and to help keep it in shape.