The Apple Push Notification service (APNs) no longer supports the legacy binary protocol as of March 2021 per the APNs provider API deadline update from Apple. Beginning with Jamf Pro 10.28.0, HTTP/2 is the default protocol for connections to APNs. This means that all mobile device management (MDM) communication, such as remote commands, configuration profiles, applications, and push notifications, is handled by the HTTP/2 protocol.