Facebook Messenger for iPhone comes with an “App lock” feature to lock the app.
You can enable this feature by following these steps:
Open the Facebook app.
Tap your profile picture in the top left.
Tap App Lock.
Enable Require Face ID.
Tap OK on the pop-up.
These options are now available to you:
- After I leave Messenger
- 1 minute after leaving
- 15 minutes after leaving
- 1 hour after leaving
Select one of the options above to set when the app locks.
That’s all. Face ID or passcode will be required to unlock the app.
Note: You can turn off the app lock at any time by disabling the “Require Face ID.”