Apple iPhone 12 mini

Press Settings.

Press Mobile Data.

Press SIM PIN.

Press the indicator next to "SIM PIN" to turn the function on or off.

Key in your PIN and press Done.

If the wrong PIN is entered three times in a row, your SIM is blocked. To unblock your SIM, you'll need to key in your PUK. The PUK can be obtained by contacting Customer Service. Please note: If the wrong PUK is entered ten times in a row, your SIM will be blocked permanently. In this case, you need a new SIM from Telstra.

Slide your finger upwards starting from the bottom of the screen to return to the home screen.