Turn Off iPhone 14 Using Buttons
Simultaneously press and hold the side button (power button) and either the volume up or down button for a few seconds, until the sliders appear.
Then drag the Power slider to the right to power off.
If you change your mind, simply press the cancel button.
TURN OFF IPHONE 14 USING SETTINGS APP
You may need to use Settings to bring up the power slider if you have a volume button or side button that is defective.
Tap to launch the Settings app from your Home Screen.
Choose General from the Settings menu, then select Shut Down from the General menu.
Drag the power slider to the right to power off.
TURN ON IPHONE 14
To power on the iPhone 14, just press and hold the Side button (power button) until the apple logo appears.
Alternatively, if your side button is damaged, connect your iPhone 14 to a USB power source using a Lightning to USB cable. The Apple logo will appear and the iPhone will boot up without needing to press any buttons.