This fingerprint feature is available in the latest Whatsapp version. The first thing you have to do is update your Whatsapp version to the latest version via Playstore.
To activate this finger print feature
You can go to the menu:
- Settings> Account> Privacy and tap the option Fingerprint lock .
- After you activate this feature, you must register your fingerprint for each time you want to open WhatsApp.
- You can also choose how long Whatsapp is unlocked after you open it. You can have the feature automatically lock the application after 1 minute or 30 minutes. If you disable the Show content in notifications' option, then WhatsApp will no longer display notifications for every incoming message.