Here is a straightforward guide for setting it up:
Access the Settings Menu: Start by launching the Settings application on your iPhone.
Locate the Action Button Settings: From the list, select “Action Button.”
Select Your Desired Action: Swipe left or right to explore and choose the action you wish to assign to the Action button.
Confirm Your Selection: Tap the Back icon, then select “Save” in the upper-left corner to finalize your choice.
Alternatively, you may configure the Action button via Accessibility:
Open Accessibility Settings: Navigate to Settings, scroll down, and tap on “Accessibility.”
Go to Action Button: Under the “Physical and Motor” section, select “Action Button.”
Designate Your Preferred Action: Choose the action you would like to assign.
Common actions for the Action button include toggling Silent mode, activating Focus, launching the Camera, or turning on the flashlight.