facelandmark-video {
    width: 640px;
    height: 480px;
}

HTML

<facelandmark-video usecamera>
    <visualization-canvas></visualization-canvas>
</facelandmark-video>

document.body.addEventListener('endrecording', (e) => {
    onEndRecording(e);
});

function onEndRecording(event) {
    const currentRecording = event.target.recording;
    const link = document.createElement('a');
    const data = `data:text/json;charset=utf-8,${
        encodeURIComponent( JSON.stringify(currentRecording)
        )}`;
    link.setAttribute('download', `${event.target.tagName}-${Date.now()}.json`);
    link.setAttribute('href', data);
    link.click();
}