MDESupportedProtocols
A dictionary that declares which media sharing extension protocols an app supports.
Discussion
Add this key to your media app’s Info pane in Xcode to declare support for one or more media device extension protocols. Each dictionary entry maps a protocol identifier to an application identifier on the remote device:
<key>MDESupportedProtocols</key>
<dict>
<key>com.example.sharingprotocol</key>
<string>com.example.myapplicationidentifier</string>
</dict>The dictionary key is the protocol’s UTTypeIdentifier, matching the value declared in a media device extension’s UTExportedTypeDeclarations. The string value is the app identifier that the protocol launches on the remote device. The value can be empty when the protocol targets no specific remote application.
When a media device extension supporting one of the listed protocols is available on the system, or you set MDESupportsUniversalURLPlayback to true and any URL-playback supporting extension is available on the system, supportedExtensionAvailable returns true and your app can observe routing events through AVSystemRouteController.
Use the AVSystemRoute.LaunchMode.application launch mode to start your counterpart app on the remote device using the configured application identifier.