How to update iPhone 7 to iOS 15
How can I update iPhone7 iOS 14.4 to 15
[Re-Titled by Moderator]
iPhone 7, iOS 14
Follow the steps in the following resource which will help you update your iPhone 7. You should be able to update to iOS 15.8.3 which is the latest version of iOS you are able to upgrade to.
Update your iPhone or iPad – Apple Support (UK)