The iPhone X lock screen has two default buttons, one is Camera and other is flashlight. Is there any way to remove/customize the flashlight shortcut? I could not find any solution for it anywhere.
On iOS 11 - the flashlight is tied to the 3D Touch feature. If you turn that off in General> Accessibility>3D Touch, then the flashlight disappears.
On iOS 12 - there's no known way to remove this with a setting on the phone or action short of jailbreaking (which would be a different question entirely on how to jailbreak)