To add a new app, click on "Add new app" at the top:
Or just register and application create screens will show automatically. Fill the information about the app.
This is a name of the app that will be used in reports.
To get Bundle ID open App Store Connect, go to "My Apps" and choose your app. At the app page find “Your Bundle ID”.
To get shared secret:
Open App Store Connect, go to my “My Apps” and choose your app.
Go to "Features" and select “In-App Purchases”.
Click on “View Shared Secret”. Generate a new one if you don't have it yet.
Open App Store Connect, go to “My Apps” and choose your app.
Under "General Information" find "Subscription Status URL", paste generated URL and save changes.