A 1010 may be diffrent than my 500 , but I dont think the roof construction is . When I cut a sky light into my bathrm what I saw was framing side wall to side wall at interior ceiling panel joints , easy to find. Trim on ceiling, and intermediate side to side framing at vent sides AC sides , With luon panel on inside ceiling and on roof , bonded with spray type expand foam . Vapor barrier over that then the alum roof
I would only attach anything to the framing . When you think you know where it is on the roof , use a real small drill bit to make sure you hit framing before you screw into it, use butel tape and dicor to seal it
You may be able to find all the framing using a stud finder from the inside
Or maybe Lance can provide a framing diagram, Northstar provided me a diagram for a camper once