Azure Notification Hubs enables viewing telemetry data in the Azure portal. Details of the metrics are available on the Notification Hubs Metrics page.
You can also programmatically access metrics. For more information, see the following articles:
Retrieve Azure Monitor metrics with .NET. This sample uses the user name and password. To use a certificate, overload the FromServicePrincipal method to provide a certificate as shown in this example.
Getting metrics and activity logs for a resource
Azure Monitoring REST API walkthrough
Note
Successful notifications mean simply that push notifications have been delivered to the external PNS (for example, APNs for iOS and macOS or FCM for Android devices). It is the responsibility of the PNS to deliver the notifications to target devices. Typically, the PNS does not expose delivery metrics to third parties.