OnePlus
Enable Face Unlock auf OnePlus
Face Unlock on OnePlus phones works separately from fingerprint unlock and from your backup pattern, PIN, or password. Until you actively register your face, the front camera has nothing stored to compare against, so the option stays greyed out on the lock screen even though the feature exists in the system.
To register your face, open Settings ➔ Security & lock screen ➔ Face Unlock. The phone first asks you to confirm your identity by entering the current pattern, PIN, or password.
After that, tap Add face data, then Next and follow the on-screen instructions. Hold the phone at eye level in decent lighting and keep your face inside the frame until the scan finishes.
Once registration completes, Face Unlock runs alongside your other unlock methods rather than replacing them. If scanning fails repeatedly, poor lighting or a covered camera lens is usually the cause, and switching to fingerprint or PIN unlock remains available at any time.
Face Unlock is generally less strict than fingerprint authentication, since it relies on camera-based matching rather than a physical sensor. For payment apps or banking logins, check whether the app still requires a stronger unlock method regardless of your lock screen setting.