How to adjust the amount of time the "lock screen" stays illuminated before the screen goes dark again?

Starting with the iPhone turned on but "asleep" -- the screen is dark -- if I briefly touch the screen or the power button, the screen illuminates to show the "lock screen." If I then do nothing else, the lock screen will stay illuminated, waiting for me to enter my passcode, for about seven seconds -- after which it will just go dark again.

How do I adjust this "seven seconds" time-period during which the lock screen remains illuminated at the lock screen level, to be a longer or shorter period of time? Or is there no way to adjust it?

iPhone 12 mini running iOS 15.4.1