Start with the entrance.
Describe the door and whether it is simply locked or the hardware appears damaged. Say who can authorize access. You can explain what happened without forcing the key or testing ways around the lock.
A missing vehicle key needs a different conversation from keys left inside. See car key replacement if no working key remains, or review estimate questions before agreeing to the work.
Keys inside, or a problem with the lock?
Say whether the door was working normally before it closed, whether the key is visible inside and whether you have a spare available. A broken key or a lock that has become difficult to turn is useful to mention at the start.
If you are waiting near Main Street shops or a busy destination, describe where you can be contacted and which entrance is involved. A business name can cover more than one door. For a parked vehicle, the location details guide is a useful starting point.