As I remember, there was a cheat to enable it in dorms while playing, but I was wondering if there's anything I can do to move objects or use the buy & build mode in apartments while playing.

In an apartment I play at the moment, the mailbox is placed wrongly, I had to move it, but I couldn't find anything about how to.

It'd be useful to use the places for build and buy out of the rented apartment in play.

I am not sure if this is the right place to post it , so apologizes.

Be aware that modifying apartments is pretty glitchy; these cheats work but may destroy your lot. The best thing is to keep a residential version of your lot (before it was ever turned into an apartment) and make your changes there instead.

That said, the cheat for changing an unoccupied apartment is:
boolProp aptBaseLotSpecificToolsDisabled false

If you want to change an occupied apartment (not recommended), you need an additional cheat:
boolProp aptSubLotSpecificToolsDisabled false

Thank you ! That helped me a lot for now <3 thanks again.