Samsung Galaxy A21s

Press and hold the Side key until your phone is turned on.

If you're asked to key in your PIN, do so and press OK.

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

Slide two fingers downwards starting from the top of the screen.

Press the power off icon.

Press Power off.

Press Power off.