Tap the Hide App button at the bottom of the menu window that appears.

If you want to add new controls, once you've removed the flashlight and camera, tap the plus ( +) sign that appears after removing the control to pull up the Control menu. This menu shows you all the controls you can add to the lock screen, including Translate and Quick Note.

OS 18 offers the most control over the look and feel of your iPhone's user interface than any other version of Apple's mobile operating system to date.