I want to install iOS 16 but it’s not available. My phone is on 15.7

The iPhone 6S/6Splus cannot update further then iOS 15.7

The iPhone 7/7plus cannot update further then iOS 15.7

The iPhone SE (2016, first gen) cannot update further then iOS 15.7

If you have an iPhone 8 or later, try and remove the beta profile (if you have that) to see if you can update after that

If you have previously used a beta version of iOS, delete the beta profile. After removing the profile, restart the phone and check again for the proper update.