Open WhatsApp
Go to Settings
Tap Privacy
Tap App Lock or Screen Lock
Turn on Unlock with Fingerprint or Face ID
Set up your device password, PIN, or biometric lock if prompted
Choose when WhatsApp should lock automatically
On Android, use the fingerprint option if available
On iPhone, use Face ID or Touch ID if available
If App Lock is not available, use your phone’s built-in app lock feature or a third-party app lock tool
Keep your device screen lock enabled to protect WhatsApp