Our 2010 Zinger ZT19RD has the same thing. I added a holder made out of ready rod, extension nut and threaded eye hook.
Our Zinger has bolt ends protruding down so I made one end a circle and attached it to the bolt near the door. This end needs some play to lift the rod holder up to attach to the door. The other end I bolted a metal conduit/wire holder using the stabilizers existing bolt, this is used for travelling/storage.
I had to put a bend in the ready rod to clear the underside of the trailer. The end that attaches to the door has a extension nut and eye hook. The threaded eye hook end was not tightened so the length can be adjusted and so the eye hook can be turned90 deg.to slip into the metal travel/storage clip.
A vinyl cap was added to the eye hook end. This rod holds the door securely and is approx. 1 inch away from the awning when the door and awning are both open. It has never popped out of the holder when travelling.