This feature allows users to add a layer of protection to their app chats and keep nosy people from seeing their chat history. It also contains a new ‘show content in notifications’ option that allows users to decide if they want to show or hide message and sender preview when the fingerprint lock is enabled.
This fingerprint lock option is enabled in the latest version of Android beta version 2.19.221. The feature is disabled by default so users would have to activate it through their WhatsApp settings:
You can enable the fingerprint lock option by doing the following:
Go to WhatsApp Settings > Account > Privacy > Fingerprint lock.
If you have already updated to the latest version, and still can’t see the feature, try to back up your chat history and reinstall the same WhatsApp version. Your phone needs to be running Android Marshmallow or higher to feature a fingerprint scanner.
When enabled, users will need to use fingerprint authentication to unlock WhatsApp and gain access. You can automatically lock your WhatsApp using three options – immediately; after 1 minute; and after 30 minutes. You may also choose from these options according to your preference. When users choose the ‘immediately’ option, the app will require the user to fingerprint authenticate every time they close and open the app.
iOS app users have a 15-minute option but this has not been included in the Android version. WhatsApp might include it in a more stable version. Android users do however have a new option. This option is called ‘Show content in notifications’, and it allows users to decide if they want to show or hide messages and the sender preview when the Fingerprint lock is enabled.
If you do not enable this option, you can still reply to messages from notifications and answer WhatsApp calls, because the authentication is only set to when you want to open WhatsApp.
Source: Capricorn Review