I want to make sure the update was completed.

Open Settings ➡️ General ➡️ Software Update: Here, it will state the current version that is installed. If there is still an update available then it will be listed. It should state that the software version and that iOS is up to date.

Axel F.

If you missed the notification of the "Update Completion"

Settings > General > About > iOS version [Check this] This must be iOS 16.1.2