Use Passcode to Power Off

That option has never been available and never will. Electronic devices, especially those with powerful non-removable batteries, need a foolproof and unpreventable way to turn them off.

Any notion that such an option could provide any meaningful security has been debunked thousands of times in these and other forums.

Adding to edclange’s reply:

Presumably, you are under the impression that requiring a passcode would allow you to locate your phone if it’s been stolen.

The physics of the matter are that a criminal will ALWAYS be able to prevent you from locating your phone; even IF it were still “on.”

PLUS, the only individuals who should ever even consider approaching suspected criminals - trained law enforcement - already have other “technical locating means” at their disposal.

An iPhone owner should NEVER confront a suspected criminal, doing so might well end VERY badly.

mibrahim14 wrote:

How don't know why but my iphone doesn't show this option "Use Passcode to Power Off", Anyone please guide me how can i use this I really need this option for security reasons

There is a very practical reason why this feature doesn't exist. Being able to force restart a phone is an important troubleshooting step, especially if the phone has become unresponsive. If you were not able to do that because you needed a password which couldn't be entered because the phone was unresponsive, you'd have brick.

You use the passcode to unlock you iPhone once it's unlocked you can power it off without typing in your passcode again