Help for bot, getting call notifications

Hi,
I'm trying to register/develop a bot, getting incoming calls notifications and answer/transfer them. My code is based on the IncidentBot . I've registered the bot in Azure with the required API permissions (MS Teams and Skype).
I've deployed the AppService and I can see (using SignalR notifications) that it works as expected when I call via PostMan the Rest API (unathorized requests).
I tried to test it either with AppService or with ngrok (reserved domain)
The Webhook is https://[service url]/callback/calling
I don't get incoming calls notifications. We want to relate the bot with a phone number to get incoming calls or (if no possible) with a group where the bot is the only one member.
It seems to me that I've not understood the workflow.My testing is (as a teams user) to call the phone number assigned to this group, or to call another user. I expected, in any case, the bot to get all incoming calls notifications at least, but I'm not succesful. I don't want the bot to have interface as a user in teams.
I would really appreciate your help.
Thanks

Start with the IncidentBot sample and trace the AppService webhook at /callback/calling, comparing it with the REST API and ngrok testing described here. The issue does not identify a file, test, concrete change, or completion criterion, so the desired bot call-notification workflow needs to be clarified before implementation.