Open WhatsApp
Open the chat you want to lock
Tap the contact or group name at the top
Tap Chat lock
Turn on Lock this chat with fingerprint or Face ID
Confirm with your device authentication
Return to the chat list
Open Locked chats to access the locked chat
To unlock, open the locked chat
Tap the contact or group name
Tap Chat lock
Turn off Lock this chat with fingerprint or Face ID
Confirm with your device authentication