Apns-221.mp4 Official

: Recorded sessions of a push notification appearing on a simulator or physical device to verify the payload's "title" and "body" keys.

: Modern APNs implementations use the HTTP/2 provider API , which allows for binary protocols, immediate feedback on success or failure, and larger payloads—up to 4 kilobytes —for creating rich applications. APNS-221.mp4

Registering your app with APNs | Apple Developer Documentation : Recorded sessions of a push notification appearing

Based on technical context, "APNS-221.mp4" is most likely a or a specific training module related to integrating or debugging Apple’s notification service. Technical Context of APNS which allows for binary protocols

: A video required by Apple to demonstrate how an app uses specific features like remote notifications.