Peer to perr audio calling with 2 person at the time only

hello , we have clone the repo from ( and i have used npm install to make the node modules after that i have used sudo make dev command to run the project . Actually we are trying to achieve the peer to peer (not video calling ) audio calling between 2 persons at a time but we are unable to do so . It would be grateful if you helped us out as we are stuck at this point .