Urgent! Forgot to return the key card when staying in an American hotel.

Room card? I never check out my card. Many hotels use it to paint the garage. The check-out card is very troublesome. Call when you leave the hotel. I'm usually too lazy to go to the front desk. You book online, such as expedia, and the hotel asks expedia for money. You only deal with Expedia. Don't worry about checking out.