Just go to Settings -> Security & Location -> Smart Lock -> Trusted Face and set it up.
Works pretty well in normal lighting conditions... but then one can set up multiple 'faces' for different lighting conditions, accessories like specs etc... Try it out with multiple 'face' setups and see what works best for you.
still did not recieve the face unlock update for indian unit.GLobal version has already recieved it,please nokia push this update as soon as possible.
@Vin_kr: Not sure if you are looking for something different or some very specific feature, but 'Trusted Face' is the mechanism to unlock your device using face recognition (a.k.a. Face Unlock).
If you haven't tried it out already, I suggest going to the settings and configuring Trusted Face... Once you have done that, your device will unlock using face recognition. In fact, when in a locked stage, if the device is able to recognize your face, you'll see an 'unlocked lock' icon appear in the bottom part of the lock screen (exactly where the fingerprint icon is shown).
Hope this clarifies...
trusted face and face unlock are different features.In trusted face device unlocks with a picture but not in face unlock and most of the global versions have already received this update but not the indian ones. https://www.youtube.com/watch?v=i1nd2wl0FOQ I hope this one clarifies the difference between them and clearly we can see here there is an option of face unlock which is not present in our devices.
This feature was included when an update come to those who bought the oreo 8.0 version,and got updated to 8.1.But we are using android 8.1 out of the box,i hope they take this matter as urgent and resolve this issue,hope to find it with the next major update maybe the android pie one