This feature needs a gateway

Remote features only work when your lock is paired to a gateway. Bluetooth alone requires you to be within range of the lock. 

• SDL Wi-Fi Gateway — Dual Band (2.4 GHz & 5 GHz)
  
• SmartDL Wi-Fi Gateway (2.4 GHz)

If you already have a Wi-Fi gateway make sure your have configured the Wi-Fi Bridge.

Enabling 'Remote Unlock' for the Smart Door Lock

1. Open your TTLock App.
2. Select the smart door lock you want to configure if you have multiple smart door locks. 
3. Tap 'Settings' -> 'Remote Unlock'
4. Tap 'Turn On'.