Campervan - secure lock

My campervan uses mainly the type of lock from the picture. To lock a door you need to press the button. I regularily forget to lock the kitchen drawer and it moves while driving. I wanted something that locks automatically but couldn't find a commercial part that could directly replace the original lock.

This thing is similar to other locks I found. It needs a metal grip at the outside to protect the lever. The parts are connected with M3 screws of varying length. You also need a small sprin