The WELOCK Door Sensor is designed for easy installation, ensuring that you can set it up without professional assistance. Following a few straightforward steps, you can secure your home in minutes 1. Insert the battery 2. Align the arrow on the component with the arrow on the door sensor, and use the 3M adhesive from the accessory list , and install them separately on the door and the door frame. 3. Download WELOCK App Please scan the code to install; it supports Android and iOS. Or click here to install. 4. Please bind WELOCK WiFiBox3 first 5. Bind the door sensor 1) Click on the left menu of WELOCK and select "Add Device.". 2) Scan the QR code 3) Enter ID and click Bind 6. After successful binding, you can see the door sensor in the device list.  For more information