How do I update my iPhone to latest iOS version?

An unit running 16.7.10 isn't capable of 17 or above. If you're trying to install 16.7.10, describe what happens.

The people on these boards are mostly other customers and can't update it in any case.

(258874)

Your tag line says that you have an iPhone X running iOS 16.

You can update an iPhone X to the latest release of iOS 16. You cannot update an iPhone X to iOS 17 or higher.

About iOS 16 Updates - Apple Support

Update your iPhone or iPad - Apple Support

Updating iOS: common issues and solutions - Apple Community