iOSProjects | contains different applications developed with Swift-5 ‍ | iOS library

So I suppose that simply referencing the iOS project in the gradle.properties is not enough.

Correct. The hands-on does not appear to describe how you'd actually integrate with Xcode. We generally use cocoapods to make this all a little simpler, but in the hands-on, you need to run :shared:packForXCode from the gradle command line to build the actual framework (you could maybe run it from Android Studio).

That should build a framework in your build dir. Look at the Xcode project in the hands-on. You will see a linked framework pointing at the KMM framework. In your prod Xcode project, you'll need to add that. In the hands-on, look in the build scripts for the one that runs gradle. You'll want to carry that over to your prod Xcode project (see here).

To manually set all that up, you'll need a pretty solid understanding of Xcode config.

If your prod Xcode uses Cocoapods, I'd suggest that route (and self-promo KaMP Kit as an example).