How to get iOS 15.3.1 on my iPhone 6s Plus?
How do I get to use this IOS 15.3.1 Version
[Re-Titled by Moderator]
iPhone 6s Plus, iOS 14
Why not? What happens when you try to install it? You can either describe the problems and what steps you have used to try and fix it, or you can just take a look at this and work with it. If your iPhone, iPad or iPod touch won’t update - Apple Support If it still won't work, see this, If you can't update or restore your iPhone or iPod touch - Apple Support