How do you enable auto lock on Hyundai Sonata?

To enable auto lock on a Hyundai Sonata, start by turning on the ignition without starting the engine. Then, press and hold the "Lock" button on the key fob for about five seconds until you hear a chime. Release the button, and the auto lock feature should now be activated. If needed, refer to the vehicle's owner manual for specific instructions related to your model year.