An Azure service that provides an integrated environment for bot development.
@Rejisha Gopan Usha Kumari Thanks for the question. Can you please add more details about the error details. Please raise a support request for subscription upgrade request, to get access to any ACS enabled subscription. Telephony Channel is currently in Public Preview, available broadly for the US-based Azure subscriptions. If you have general questions , you can reach at telephony-preview@microsoft.com.
Please follow the sample for botframework-telephony.