https://developer.apple.com/documentation/app_clips/testing_your_app_clip_s_launch_experience This link, and setting is needed in web server.

https://developer.apple.com/forums/thread/651461 https://developer.apple.com/forums/thread/654263 Xcode does not have a validation tool to verify app clip size. Sizes are validated when submitting to App Store Connect bundled app code and resources counts in the 10MB limit I think we need to upload the IPA to app store to see the download size.

I am going to point you to the Creating an App Clip with Xcode documentation, specifically, the Keep Your App Clip Small in Size section. This section has a great tip for for exporting your App Clip from Xcode, and how to see the App Clip's uncompressed size. Succinctly, you can export your App Clip by "archiv[ing] the app clip’s corresponding app, open the Organizer window, select the archive, and click Distribute App." Then, you can "[e]xport the app clip as an Ad Hoc or Development build with App Thinning and Rebuild from Bitcode enabled." Upon exporting, in the output folder you chose to export to, you will see a Thinning Size Report.txt file. This file will include the uncompressed size of the App Clip, which you can use as a guide for trying to ensure your App Clip fits under 10MB. Thanks very much, I tried to unzip and see there is a resource bundle be packed to app clip, that cause to problem,it uploaded to itunes connect successfully after removing it. Now I am trying looking at the linkmap file and try to remove some big classes. Many thinks for your reply.

Same iOS 15.0 Mac mini 2018 Xcode Version 13.0 (13A233) iOS 14 devices have no problem, so I think there's something wrong with iOS 15 or Xcode

It works in after iOS 13.0 with Xcode 13.2.1 !

github.com/facebook/facebook-ios-sdk/issues/1501 Disable LTO solve the problem