getDisplayMedia демонстрация экрана

Есть вот такой код:

<style>
    #video {
  border: 1px solid #999;
  width: 98%;
  max-width: 860px;
}

.error {
  color: red;
}

.warn {
  color: orange;
}

.info {
  color: darkgreen;
}
</style>


<p>This example shows you the contents of the selected part of your display.
Click the Start Capture button to begin.</p>

<p><button id="start">Start Capture</button>&nbsp;<button id="stop">Stop Capture</button></p>

<video id="video" autoplay></video>
<br>

<strong>Log:</strong>
<br>
<pre id="log"></pre>



 <script>
    const videoElem = document.getElementById("video");
    const logElem = document.getElementById("log");
    const startElem = document.getElementById("start");
    const stopElem = document.getElementById("stop");
    // Options for getDisplayMedia()
    var displayMediaOptions = {
        video: {
            cursor: "always"
        },
        audio: false
    };
    // Set event listeners for the start and stop buttons
    startElem.addEventListener("click", function(evt) {
        startCapture();
    }, false);
    stopElem.addEventListener("click", function(evt) {
        stopCapture();
    }, false);
    console.log = msg => logElem.innerHTML += `${msg}<br>`;
    console.error = msg => logElem.innerHTML += `<span class="error">${msg}</span><br>`;
    console.warn = msg => logElem.innerHTML += `<span class="warn">${msg}<span><br>`;
    console.info = msg => logElem.innerHTML += `<span class="info">${msg}</span><br>`;
    async function startCapture() {
        logElem.innerHTML = "";
        try {
            let screen = await navigator.mediaDevices.getDisplayMedia(displayMediaOptions);
            videoElem.srcObject = screen
            sendInfo(screen);
            dumpOptionsInfo();
        } catch (err) {
            console.error("Error: " + err);
        }
    }

    function stopCapture(evt) {
        let tracks = videoElem.srcObject.getTracks();
        tracks.forEach(track => track.stop());
        videoElem.srcObject = null;
    }

    function dumpOptionsInfo() {
        const videoTrack = videoElem.srcObject.getVideoTracks()[0];
        console.info("Track settings:");
        console.info(JSON.stringify(videoTrack.getSettings(), null, 2));
        console.info("Track constraints:");
        console.info(JSON.stringify(videoTrack.getConstraints(), null, 2));
    }

    function sendInfo(data) {
        console.log(data);
    }

</script>

Есть rtmp сервер.

Подскажите, пожалуйста, как мне передавать туда демонстрацию экрана?

Спасибо