1. Find "SIM card lock"
Slide your finger down the display starting from the top edge of your mobile phone.
Press the settings icon.
Press Lock screen & security.
Press SIM card lock.
2. Activate or deactivate use of PIN
Press Lock SIM card to activate or deactivate the function.
Key in your PIN and press OK.
3. Return to the Home screen
Press the home icon to end the session and return to the Home screen.