I used the Apple's source code in order to try the feature and created a web-site on heroku and added AASA file under the /public folder.
After that I archived the app with development distribution and installed it using Xcode Devices & Simulator section. Then I also added local experiences on real device adding my app url prefix (fe. heroku-app-124.herokuapp.com) and App Clip's bundle id.
But whatever I tried I couldn't get it working. Below I share my AASA file.
"appclips": {
"apps": ["TEAMID.com.company.AppClip-Sample.Clip"]
}
}
Also in Xcode It's been added the herokuapp URL like below
appclips:app-sample-01031.herokuapp.com