Call the front desk of the hotel and ask if your relatives live there.

The hotel won't and can't tell you, because for hotel guests, everything is confidential. Usually you are asked to call the person you are looking for directly. If it is really urgent, the front desk will also consult the guests first, and the room number can only be told after the guests agree.

For rooms that do not require confidentiality, ask the guest what information he wants to inquire, check the computer and ask the guest's name. Then go to a hidden place (cashier's office) or ask the assistant manager of the switchboard and lobby to call the guest and tell Mr./Ms. XXX that he/she is looking for you. Can you ask him/her to go to the room and ask for a secret room? Tell the hotel that there is no room for guests to register, and suggest to contact by other means.