You may be able to tell from looking at the inside back wall. Often Panels meeting, outlets, staples, window frames are good clues to where the studs are running.
You can also use something like wallbot that we all see advertised on FB or a good stud finder with a deep scan setting.
You could contact Forest River and see if they have a blueprint that would lay out where they are but even with that in hand, I would want some verification through one of these other methods before I put a drill bit to the outside of my camper skin.
2020 Chevrolet 2500 LTZ, 2019 Forest River Wolfpack 23Pack15, 2014 EZGO Golf Cart.