Answer by Grish Grigoryan for WebRTC ontrack is not called

I have made some correction on your code and now it works.Also I have changed callbacks with promises.

var localVideo = document.querySelector('#local'),remoteVideo = document.querySelector('#remote'),localConnection, remoteConnection;navigator.getUserMedia({video: true, audio: false}, function (stream) {    localVideo.srcObject = stream;    startPeerConnection(stream);}, function (error) {    alert("Camera capture failed!")});function startPeerConnection(stream) {    var configuration = {        offerToReceiveAudio: true,        offerToReceiveVideo: true    }    localConnection = new RTCPeerConnection({configuration: configuration, iceServers: []});    remoteConnection = new RTCPeerConnection(configuration);    stream.getTracks().forEach(        function (track) {            localConnection.addTrack(                track,                stream            );        }    );    remoteConnection.ontrack = function (e) {        remoteVideo.srcObject = e.streams[0];    };    // Set up the ICE candidates for the two peers    localConnection.onicecandidate = e => !e.candidate        || remoteConnection.addIceCandidate(e.candidate)            .catch(e => {                console.error(e)            });    remoteConnection.onicecandidate = e => !e.candidate        || localConnection.addIceCandidate(e.candidate)            .catch(e => {                console.error(e)            });    localConnection.createOffer()        .then(offer => localConnection.setLocalDescription(offer))        .then(() => remoteConnection.setRemoteDescription(localConnection.localDescription))        .then(() => remoteConnection.createAnswer())        .then(answer => remoteConnection.setLocalDescription(answer))        .then(() => localConnection.setRemoteDescription(remoteConnection.localDescription))        .catch(e => {            console.error(e)        });}