Welcom to the Apple Support communities “shinoesi”!
It seems like that your iPhone got stuck , Try to force restart your iPhone by the steps below:
Press and quickly release the volume up button, press and quickly release the volume down button, then press and hold the side button. When the Apple logo appears, release the button.
after that try to update it again , if you already downloaded the update remove it and reinstall it again by the steps below:
- Go to Settings > General > [Device name] Storage.
- Find the update in the list of apps.
- Tap the update, then tap Delete Update.
- Go to Settings > General > Software Update and download the latest update.
All The Best!
❐‿❑