How can I update my iPhone 11 Pro Max to iOS 16.5?
I want to update ISO 16.5
[Re-Titled by Moderator]
iPhone 11 Pro Max, iOS 15
As a rule, you cannot pick and choose an intermediate version of iOS.
Your phone can run iOS 18, so it should be offering you the latest release of that; and maybe also the latest release of iOS 15 (if that is the major version you are currently running).
I believe the windows during which you could have updated to iOS 16 and 17 have passed.