I am able to chat using business accounts alright. However, when I try to add audio or video to these conv(ersation), like conv.audioService.start(), I get commandDisabled error.
I was not able to find satisfactory explanation of this when I did Google Search, hence the question here.
Audio and Video conversations initially were available for Public Preview product keys only. Later they had updated the documentation and added audio/video to General Availability keys support. Indeed, take in account (state at Jun 12 2017), that while with the preview keys your app will try make an audio/video call in Chrome or Firefox, with the GA keys it will not (CommandDisabled) - they aren't supported browsers (only IE, Edge and Safari will do).