You aren't going to believe this but I'm locked inside my camper ! Apparently when my wife left to pickup our grandson , she locked the camper door but didn't return the key to it's proper position. I...
Did your inner plate not have provisions for unlocking from the inside? I know mine does. If all else fails, you may be able to fit a knife/screwdriver inbetween the door and the wall to push the sticky outty part (technical term) back into the door.
That's pretty much how I get into my house when I've locked myself out.