Using the Construct 3 build service you can create an Xcode project, and use that to test and publish your game on iOS. This feature is only available to subscr...
sounds like you opened the .xcodeproj file instead of the .xcworkspace file in xcode. even if thats not the case, simply saying "failed due to apple bug" gives zero information on how to solve your problem... but based on "missing web assembly" comment, my best guess is you opened the wrong file.