Apple adds additional information on notification delivery metrics to Push Notification Console.
The Push Notifications Console now includes metrics for notifications sent in production through the Apple Push Notification service (APNs). With the console’s intuitive interface, you’ll get an aggregated view of delivery statuses and insights into various statistics for notifications, including a detailed breakdown based on push type and priority.
Apple Developer
Apple Developer: New delivery metrics now available in the Push Notifications Console
Reference: Apple launches push notification delivery metrics monitoring for developers