Use WhatsApp Fingerprint Lock feature like this
The fingerprint lock feature in the beta version of WhatsApp can be enabled by going to Settings. It is worth noting that to use this feature, the phone must have at least Android Marshmallow, as well as a fingerprint scanner. As we told you that even in beta version you will find this feature disabled by default, so let’s know what is the way to enable it…
Enable fingerprint lock feature in WhatsApp like this
1) First open the WhatsApp app.
2) After this, click on the three dot menu and go to Settings.
WhatsApp Fingerprint Lock Update: Fingerprint lock feature came in WhatsApp
3) After going to Settings, you will get the option of Account here.
4) After clicking on the account, select the Privacy option.

WhatsApp Fingerprint Lock Update: You can enable the feature by going to Settings
5) After clicking on privacy, you will see the option of fingerprint lock at the bottom. It can be enabled by clicking on this option.
As soon as you enable this feature in WhatsApp, you will get three options to automatically lock – immediately, after 1 minute and after 20 minutes. Till when the stable update of this feature will be released, no information has been received about it at the moment.