WhatsApp has already introduced many privacy features for users. One such thing is WhatsApp Lock. As a part of that, TouchID, FaceID, and Fingerprint Unlock have been provided to the users. All this helps the user to keep his account from being seen by others. Along with this, fingerprint unlock has been added. People who get it will have to use TouchID or FaceID (iPhone) or fingerprint unlock (Android). This feature is available on Android and iOS platforms. Once it is obtained, use fingerprint or face WhatsApp. It should be noted here that even though the app is locked, users still have the facility to make phone calls.
To lock an iOS smartphone
• Open WhatsApp settings.
• Privacy should be selected as the top and screen lock.
• Turn to Require TouchID or Require FaceID.
• Standby mode means selecting how long both of these are required.
(If both of them are not unlocked then you can enter with a passcode on your iPhone)
Open settings for disabled. Tap Privacy - Hit Screen Lock - Require ID or Require Face ID to turn off.