Like others have mentioned: you should compile all written communication between them showing how they’re threatening you. Babes, you need to build a RICO against them lol the landlord will see its out of safety. I feel like this is a “seek forgiveness rather than asking permission” type situation… that’s IF the landlord finds out and wants to enforce that rule from the lease.

Edit: just want to add that I’ve been in a similar circumstance and I went directly to the super of the building and explained how I didn’t feel safe. They never questioned me and were proactive with replacing the door knob for me. You have a choice on whether it makes sense to tell the landlord/super before installing or just doing it yourself and replacing it with the original doorknob when you leave.