To enable the authentication on your WhatsApp, you need to make sure you are on the latest version of the app ie 2.19.20. For this, you need to head to the AppStore and update the app from there. Once done, open WhatsApp and go to Settings > Account > Privacy > Screen Lock and enable the option that says ‘Require Touch ID’. In the following screen, you get different options of time, which is basically the time after which the app would lock down itself. Select from any of the provided options accordingly. That’s it! Now every time you open the app, it asks you to authenticate yourself using either the Face ID or Touch ID, depending on your device’s hardware. A thing to note here is that to be able to use the authentication option to lock/unlock your app, you need to have the option set up on your device. Irrespective of whether the authentication is enabled or not, you can still see the incoming notifications (if not disabled) and quick reply to them. However, to get into the chat and indeed the app, you need to authenticate. The new feature is currently available via update for iOS users only. However, it’s highly likely that the update for Android could soon be hitting the Play Store. We are not sure what took them so long to implement such a basic security/privacy feature, but glad it’s here finally!