Turn use of phone lock code on or off
The phone lock code prevents others from accessing the contents of your mobile phone (pictures, messages etc.). When the phone lock code is turned on, it needs to be used every time you turn on your mobile phone and when it has been in sleep mode.
Find "Touch ID & Passcode"
Tap Touch ID & Passcode.
Turn on use of phone lock code
Tap Turn Passcode On and key in a phone lock code of your own choice twice.
Turn deletion of data on or off
Tap the indicator next to "Erase Data" to turn the function on or off.
If you turn on the function, tap Enable.
Turn off use of phone lock code
Tap Turn Passcode Off and key in the phone lock code.
Return to the home screen
Tap the Home key to return to the home screen.