Safety ideas for son who escapes

[richmond44]

Hello
Any ideas/recommendations on what you use to keep your child safe on holiday. We are having a short break in a holiday cottage in a few weeks time and my son is not safe to be left in a room that he can escape from at night. I wondered if anyone used and could recommend a temporary door lock or something else that would fit a door from outside to keep child safe. I have seen a lot advertised to lock a room from inside but not one from outside. It would need to stop him getting out of a room with an inward opening door.
Thank you.

We used to have a travel stair gate that folded up. Door sensor alarms can be useful too you can just blu-tac them to doorframe

We've used these before.

Thanks for the ideas.
Richmond