How can I receive a notification/event when camera is turn on/off in video calling

[quangvinhvux]

Hi @TatankaConCube i have some question: 1, How can I receive a notification/event when camera of local or remote is turned on/off when video calling? i have tried MediaStream.onAddTrack and MediaStream.onRemoveTrack seem it not work for this. 2, exactly onSendOffer, onSendAnswer for what ? did it send event to another opponents user? how i can use that? 3, can i send an custom event to another opponents? how i can do that? 4, message field in RemoteMessage of onBackgroundMessage function not showing full chat message when app terminated or in background, how can I fix this? looks like it's limited to 10 characters of chat message.

thank @TatankaConCube for your woking.