Provisioning profile
An Apple file that ties an app's bundle identifier to a signing certificate and allowed capabilities, and for development builds, to specific devices.
Definition
Every iOS app and app extension needs one to be signed and installed. Development profiles list the devices a build can run on; App Store distribution profiles allow uploading to App Store Connect. Xcode's automatic signing creates and renews them; CI systems use an App Store Connect API key or tools such as fastlane match.
In practice
The notification service extension needs its own App Store profile, or the archive fails to export.