Thanks for reaching here! PNS telemetry/feedback is enabled on Standard
SKU namespaces.
You do not need to configure storage accounts.
The docs for the relevant APIs are below:
Get per-message telemetry: https://learn.microsoft.com/en-us/rest/api/notificationhubs/get-notification-message-telemetry
Get PNS feedback container URI: https://learn.microsoft.com/en-us/rest/api/notificationhubs/get-pns-feedback
Hope this helps, Let us know if further query or issue remains