The Swagman Quad S64692 that you have is not rated for use on a hitch behind a travel trailer. For a 4 bike Swagman bike rack that is confirmed as a fit the Trailhead part # S63381 is a confirmed fit.
You'd need a hitch installed on your RV frame like the Curt Multi Fit part # 13703 which is designed to attach to trailer frames that are between 22 and 72 inches apart on the outsides. view full answer...