Our 2017 came with one that is stashed behind the couch on a couple of brackets. The trailer we had before the ACE had bunks but no ladder. We found this one on Amazon. We had to cut a few inches off the bottom legs and it worked fine. Just check to make sure it’s long enough as I think the ACE bunk is higher than the one we had in the trailer
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1