In the Identity section, update the Build identifier to a unique
build number used to track this build on App Store Connect.
Each upload requires a unique build number.

Create an app bundle

Run flutter build ipa to produce an Xcode build archive (.xcarchive file)
in your project’s build/ios/archive/ directory and an App Store app
bundle (.ipa file) in build/ios/ipa.

Consider adding the --obfuscate and --split-debug-info flags to
obfuscate your Dart code to make it more difficult
to reverse engineer.

If you are not distributing to the App Store, you can optionally
choose a different export method by
adding the option --export-method ad-hoc,
--export-method development or --export-method enterprise.