I believe they come with one! Mine did. I'm just pondering something for the inside, because grabbing onto the screen door frame is not allowed! Since I had "all white" trim, Tammy asked if I wanted the assist handle white also, to match the "belly band" and the exterior lights. If you look closely at the some of the posted pictures on "Show your Escape", you can see them.. On the Escape web site home page, the newer ones have the handle. The main pictures are of the older ones.
Congratulations and best wishes. Hopefully you will show us your new Escape too.