1. Go to 
Settings > 
Apps > App lock.
2. Tap
at the upper-right corner of the phone.
Settings > Apps > App lock.2. Tap
at the upper-right corner of the phone.
3. Manage App lock settings.
• Tap Lock settings to choose when to apply App lock. You need to verify your App lock password when you open a protected App in the applied time.
• Tap Hide notification content to select which Apps to hide notification content. The feature allows you to see You have a new message instead of the actual content when you receive a notification.
• Tap 
to enable Unlock all apps at once.
• Tap 
to enable Lock all apps.