One, how to lock hotel doors
Typically, hotels provide guests with key cards. After checking in at the front desk, guests will receive a key card, which serves as the key to their room. once inside the room, guests should lock the door. This prevents unauthorized individuals from entering the room when someone knocks on the door from the outside.
On the door, there will be a security chain or similar device. The security chain also provides excellent protection. Even if the door is opened, only a small opening will be created.
II. Hotel door locking tips

1、Secure the second-layer lock.
Even for locks on our own doors, most have a double-layer locking mechanism. This hidden lock is designed to ensure that the inner lock is securely closed, preventing unauthorized access even from the outside, even with a key.
2、Use a clothes drying rack to support it.
This is my preferred method. Even if the door lock is very secure, I habitually use a clothes drying rack to apply pressure against it. I've seen this done in many hotels, where the rack is simply placed against the doorknob. Even if someone manages to open the lock from the outside, it would be very difficult for them to enter.
3、Chain link
Some hotels use a chain that attaches directly to the lock, making it virtually impossible to open.
4、Chairs
Find a chair with a backrest that can be leaned against the door handle, providing some protection. However, the chair's backrest must be higher than the door handle for this to work effectively.