Background Assets how to test your extension and to simulate its entry points.
Great question! We recognize that this is a current limitation with developing a background assets extension. We're working on a solution that will help you trigger your extension entry points.
We'll update the documentation once the tool is available. [https://developer.apple.com/documentation/backgroundassets)
Xcode 14 Beta 3 has been released today, which includes support for simulating the extension on an attached iOS device.
man backgroundassets-debug
How do I set breakpoints in the extension for debugging？