Locking a door without a key can be a useful skill to have in case of an emergency or if you’ve lost your keys. There are several methods you can use to lock a door without a key, depending on the type of lock and the materials you have available.
One common method is to use a credit card or a thin piece of plastic to shim the lock. This works by inserting the card into the space between the door and the door frame, and then pushing it in until the latch is released. Another method is to use a bobby pin or a paperclip to pick the lock. This is a more difficult method, but it can be done with practice.