How to use Face ID or Touch ID for WhatsApp
After the latest update you will now be able to lock WhatsApp with Face ID and Touch ID. For this you need to go to Settings> Account> Privacy> Screen Lock. After going to the screen lock, this application will show you the authentication method available – Face ID or Touch ID. You can choose any of them. If you want, you can set biometric authentication immediately or at one minute, 15 minute or 1 hour intervals.
Beyond that, WhatsApp will still be able to respond to messages directly from the notification panel and take calls without biometric authentication. The way Outlook is unlocked with biometric authentication. Face ID or Touch ID will unlock WhatsApp in exactly the same way.
It is worth noting that Google Pay already supports Face ID and Touch ID biometric authentication. You will need to download the latest version of WhatsApp from the App Store to experience the new changes. The size of the app is 137.7 MB and it will work on iPhone models equipped with iOS 8.0 and above.