Required for sending push notifications on Android
Go to the detail view of your app on the Twixl Distribution Platform, then select "Notifications' from the top menu.
Now enter the Server API key in the correct field.
In the build settings of your app on the macOS app (under "Article-based app" or under "App Store Kiosk - Basic Settings"), paste the Sender ID number in the field "Google Cloud Messaging Sender ID".
You have now configured push notifications for Android in your app and are ready to create the build.