My recent App Store upload gave me this error:
iTunes Store operation failed.
Missing required icon file. The bundle does not contain an app icon for iPhone / iP
I also faced the same problem, I created an app icon by this URL:
https://appicon.co/
for iPhone and iPad. It gives me a .zip file, I unzip it and move "AppIcon.appiconset" in my application's xcassets.
Now clean the project and create a new archive and upload it to the AppStore and it worked,
Thanks