A rear-closure warning can refer to a trunk, hatch, or liftgate, depending on the vehicle. While parked, check that cargo is not interfering with the latch and use the normal closing procedure.
Do not drive with an unsecured closure or force a powered liftgate against its mechanism. If the closure is secure but the alert persists, note whether its interior light or power function behaves unusually. Share those observations with 12th Street Auto Care Center.