Nexmo Get Call on WebApp using Web socket

I am creating an application in NodeJS using Express and Nexmo Voice API.

The Scenario is to get a Inbound call in the Web Browser of our Agent, So that he or she can get details of the client in the CRM

Nexmo allow us to use web socket endpoint and i got it to make call and get it to desktop, but dont know to make it accept calls and send replies from the agent.., I dont know how to stream audio two way..any help?