How do I update ios 16.0

Did you try to follow the steps mentioned in this article, to update your iPhone?

Update your iPhone or iPad - Apple Support

Or, if you are using a computer or Mac:

Update your iPhone, iPad, or iPod touch with iTunes - Apple Support

Update your iPhone, iPad, or iPod touch with the Finder - Apple Support

Available iOS updates also depend on the supported, built in hardware for each iPhone model:

iOS 16 and iPadOS 16 are compatible with these devices - Apple Support

Ingo2711 wrote:

Availlable iOS updates also depend on the supported, built in hardware for each iPhone model:

iOS 16 and iPadOS 16 are compatible with these devices - Apple Support

If your (the OP's) iPhone is not on this list, you will not be offered an update to iOS 16.

If your iPhone is compatible with both iOS 16 and iOS 17, you might be offered an update only to iOS 17 (the later version).

If you own iPhone 8 or newer, you can update to iOS 16. If you iPhone 7 or older, you cannot.

I would like to up date to iOS 16.0

Own iPhone 7 Plus, need to update