The latest iPhone release is important and includes features and bug fixes—and an important change to Apple Intelligence ...
The new build of iOS 18.3, which is only for the iPhone 11, likely focuses on a specific bug fix, as those handsets cannot run Apple Intelligence.
If you have an iPhone 11, you should be able to find the new update in the usual place under Settings > General > Software Update. You should see an iOS 18.3 update here even if you already updated to ...