Hi @Francis Ossai ,
Azure Communication Services is a platform that supports lots of different scenarios. You can build out the functionality you want on top of our APIs. It sounds like you'd be interested in the calling functionality.
You can check out more of our SDKs and Samples on our GitHub, as well as file issues if you have any problems or feedback!
As for the error you are seeing, we experienced an incident a few days ago that was resolved, could you give it another try and see if you are still getting the same error?