WhatsApp will introduce fingerprint authentication to block access to content to unauthorized persons.
The WhatsApp Beta Info site has found how the beta version 2.19.221 supports the new feature but it is necessary to reinstall the application if it is not shown. If it is visible, you will have to wait before you can use it.
To activate this feature you will need to go to: settings -> account -> privacy. Among the options that will be available in WhatsApp there will be the choice to block the app immediately, after 1 minute or 30 minutes. Furthermore it will be possible to choose whether or not to show information in notifications.
It is not clear when fingerprint unlocking will arrive officially and for everyone on Android. The latest information in this regard dates back to January 2019, but now we are very near to the release date of the whatsapp version for all users. The only condition is to have a fingerprint reader on the smartphone.