I believe the Outback frame is a BAL Huck-bolt frame, which means it is very lightweight construction and cannot safely support the addition of a hitch receiver whether for a cargo carrier or not. I wanted to add one to my 2019 Passport with the same type of lightweight frame and I couldn't find a qualified fabricator who was willing to touch it due to the liability.
One good bump and that 100 lbs. going up, comes down with the force of 500 lbs. or more and will tear the back end of your camper off and leave it in the middle of the road, along with the carrier and everything that was on it. Different models have receivers installed from the factory that were designed and engineered to be there. Even then, I still wouldn't hang anything off the back unless the hitch and frame was seriously beefed up (like another user on here did to his)