SimpleIvrBot sample doesn't answer the calls

Hello everyone,
I'm trying to run the SimpleIVRBot following the instructions in the README file (https://github.com/microsoftgraph/microsoft-graph-comms-samples/blob/master/Samples/V1.0Samples/StatelessSamples/SimpleIvrBot/README.md) but the bot is not answering the incoming calls.

I went through all the steps described:
created the application
created the bot using the Bot Channels Registration.
Authorized the application
Updated the appsettings with appID, secret and base url
Added the Teams call channel including the base URL get by publishing the application from VS
added the Bot in teams.

My expectation is that the Bot should automatically answer all the calls for the user where I added the bot but it doesn't.
I don't get any error either.
Finally, the App Insights are enabled but they didn't even detect any failed attempt to connect.

Is something missing form the README instructions?

Start with the SimpleIVRBot README and compare each listed setup step with the reported application, bot, Teams call channel, appsettings, and published base URL. Reproduce an incoming call and inspect App Insights for evidence of whether the bot receives it. Done means identifying the missing prerequisite or documenting that the README instructions are sufficient.