Can I update my iPhone 7 from iOS 15.8 to iOS 16.7?

You cannot update your iPhone 7 to iOS 16. For the iPhone 7, a phone that originally ran iOS 10, iOS 15 is the end of the line.

The latest release of iOS 15 is iOS 15.8.4. If you are still running iOS 15.8, I would suggest updating to iOS 15.8.4, to get the latest bug fixes and security updates for your phone.

About iOS 15 Updates - Apple Support

An iPhone 6s, iPhone 6s Plus, iPhone 7, iPhone 7 Plus, or iPhone SE 1 isn't capable of 16 or above; they require an A11 or better CPU.

(260023)

Oh, sorry, I was wrong, the latest it can run is 15.8.4 and not 15.8.2, thanks!

Your iPhone 7 does not have the required hardware to run iOS 16, the max iOS update your iPhone 7 can run is iOS 15.8.2