IWatch says need newer iOS? How do I get latest when pairing to iPhone 7 Plus?

The new Apple Watches require an iPhone 8 or later with iOS 16 or later. An iPhone 7+ cannot be updated to iOS 16. Sorry.

You have two options:

1. Return the watch for refund as it is NOT compatible with your iPhone 7 Plus - OR
2. Buy a newer more modern iPhone, which can run iOS 16, which is required for your watch