Set up attribution for iOS

A short initial setup is required for iOS attribution.

1. Navigate to Attribution Settings.
2. Enter your app's iTunes Package ID, which is the number that appears at the end of your app's URL in the iTunes App Store.
   Enter only the number (e.g. 551244656), not the entire URL (e.g. https://itunes.apple.com/us/app/parking-time-meter-tracking/id551244656).