How can get the END CALL message by Bluetooth

We build a VoIP APP, but it doesn't support CallKit now.

The iPhone connects another device (for example : a device in a car likes carplay ) by bluetooth(HFP/A2DP) first.

The user opens this App and join the VoIP, he can talk with other people using the device, it works well.


There are 2 UIs in the device,

The first UI : there are play/stop/next/previous button in the UI, we click this button, the App can receive the message by the MPRemoteCommandCenter.

The second UI : there is a END CALL button in it, when I click the button, we can't any message.


I watch the iOS system log:

bluetoothd Received call hangup event (AT+CHUP) from device <private>

bluetoothd Found ongoing virtual call - Aking device and notifying upper layers.


So I think the device has send a message to iPhone by bluetooth, but the App can't receive this message. I try it using the MPRemoteCommandCenter/CTCallCenter, but failed.

How can get this message?