How can I update my iPhone 7 Plus to iOS 17?

I’m sorry, but only iPhones in the iPhone X (Ten) product line and newer support iOS 17. You can see the full list of supported devices here:

iPhone models compatible with iOS 17 - Apple Support

There is no way to update any older iPhone to the software.

Hope this helps!

Sorry, but the iPhone 7 cannot even update to iOS 16, much less iOS 17.

You need an iPhone 8 to run iOS 16

You need an iPhone XR or higher model to run iOS 17 and iOS 18.