Steps for how to add key fob on TTLock app: 1. Turn on the Bluetooth on your phone and stand nearby your lock. 2. Turn on the TTlock and Click "Cards". 3. Click "Add Card" and choose one from permanent, timed, or recurring. 4. Place the card against the card reader sensor on the smart lock after connection. After you stored the data on the app, you can unlock your smart door lock by card, just place it against on sensor, and the lock will unlock within a second, suitable for children, family members, tenants, etc.