How to get the key out when it accidentally falls into the elevator door?

If you are an elevator maintenance worker, you must have dropped the triangle key. It doesn't matter, you just fall into the well and buy another one. If you are not an elevator repairman, you would rather change the lock than try to get it back, because it is dangerous. Triangle keys for elevators are very cheap, 3 sets of 10 yuan, and they can also light the windows and toilets on the car, hehe.