An error occurred while updating my iPhone 11 to iOS 16.2

In addition to the above, ensure no add-on VPN client installed (don’t merely disable it, remove it entirely and restart), ensure no beta profile is installed, restart the Wi-Fi router, delete the existing download (Settings > General > iPhone Storage > find the update file, and delete it), and if the above reply and this all fails, connect to use a Mac or Windows PC and update there. Or make an appointment at an Apple Store or Apple authorized service provider, or “borrow” a computer.

How to uninstall iOS or iPadOS beta software - Apple Support

Learn how to update your device manually if you're using a Mac with macOS Catalina or later, or if you're using a Mac with macOS Mojave or earlier or a Windows PC.

Cycle power on your phone, enable Wi-Fi on the phone, connect to a charger, and ensure that you have sufficient remaining storage on the iphone to receive and install an update to iOS 16.2. If the issue was network related, wait a while before attempting to install iOS 16.2.