I had that happen this past fall. Found the license plate in the yard.
The RV dealer had a metal license plate bracket that we used to attach the plate to the rear bumper. I did not want to have the stupid plastic tabs that would just break again.
HTT: "EscapeII" 2016 Shamrock 23WS (current)
PUP: "Escape" 2010 Rockwood HW 277 (gone)
TV: "Bruce" 2011 Dodge Durango V8 Hemi Crew
Just us gals (me, Sis and our daughters)
Traveled 19520 miles and 209 nights in 7 years and counting