Check that your lock makes a sound when you open it. If not, it is necessary to: a) reset the padlock by removing the battery and putting it back in after 2-3 seconds. b) If it does not sound either, the battery must be replaced. If it emits sound, go to the My locks section of the application menu and click on the black padlock icon located in the upper right and the application will start searching for your anti-theft device. When a NETLOCK lock appears on the screen, select it by tapping on it on your screen and continue with the synchronization. If your lock rings but the application cannot find your lock, open a support ticket in the application and we will contact you as soon as possible.