This is the product I was thinking of when I described a locking device in my earlier post ....
Our habitation door lock is that extra bit of security added from the inside for when you are sleeping or away from your motorhome, taking less than 2 seconds to fit and remove will make entry through the habitation door from the outside difficult for intruders. Laser cut and powder coated...
www.atefabricationandweldingltd.com
A little expensive for the cost of the materials, but not too expensive to go to the bother and hassle of fabricating your own either. £20 seems a reasonable price for that peace of mind and security it offers.
No idea if there are other products out there the same. (no doubt you can get one that looks the same from TEMU that is made out of a cereal box though).
As an aside, I don't know about other folk, but I am terrible at putting my keys down in the motorhome and then trying to fidn them. You could attach this lock to your motorhome keys and then not only will you always know where the security lock is to use, you will know where your keys are at night time