Open the SOREX SmartLock app and select the lock to which you want to add a door sensor.

Then open "Settings" and select "Door sensor".

Tap on "Add door sensor". Press and hold the reset button for 2 seconds.

Click on "Next" when the light flashes quickly.

The door sensor should now appear in your app. Click on the "+" to complete the installation process.

Note: If the door sensor cannot be added, repeat the steps above or reset the door sensor and try again.