How do I update my iPhone 7 to iOS 17?

When the iPhone 7 came out in September 2016, more than eight years ago, it ran iOS 10.

You can update an iPhone 7 to the latest release of iOS 15 – currently iOS 15.8.3. You cannot update it to iOS 16 or higher. iOS 15 is the end of the line.

About iOS 15 Updates - Apple Support

kendria83 wrote:

How to update my phone yo 17 ios

On an iPhone 7, that is simply NOT possible. The highest iOS version an iPhone 7 can run is iOS 15.8.3. If you need a phone which can run iOS 17, you'll have to retire you now old iPhone and buy a new or at least much newer iPhone.