[Mikendebbie]

There are no construction details available. Back in 2013 or so I had a Jayco and Jayco happily abliged my request for framing plans. Keystone does not do that. I think they will tell you to go thru your dealer. The good news is that there are lots of smart folks that may be able to advise you on your solar install. There are several factory tour videos available that will give you a visual look at the roof construction. I have not looked for a factory tour video showing a 2022 model, but you can start by searching YouTube for Home with the Hoopers Keystone factory tour (2019).
The screen shot below is from that video.