Microsoft Teams Voice Developer

Here is the scope:

1. We have an application that we want to host inside MS Teams as a tab; We used iframe at the moment, I need someone to use SDK to embed our application in Teams

2. Next, when a call comes in to Teams, we want to get a "call arrived" event to our application;

3. At this point, we want to extract a custom value from SIP URI when call is ringing in Teams; this custom value from the SIP URI needs to be accessible to our app thats embedded in Teams

4. When Teams User 1 transfer the call to Teams user 2, we want to make sure that SIP URI custom vaIue is retained (not lost);

Let me know, if any one that can assist;

Thanks