I'm getting an error from Apple when I send the IPA to the store; they send me an email:
Hello,
We noticed one or more issues with a recent delivery for the following app:
Login 360
App Apple ID 6760033427
Version 1
Build 1
Please correct the following issues and upload a new binary to App Store Connect. ITMS-90426: Invalid Swift Support - The SwiftSupport folder is missing. Rebuild your app using the current public (GM) version of Xcode and resubmit it.
Apple Developer Relations