my messing w/ msedge dev read aloud. ONLY RUN IN edge dev. i give up, so it wont work properly

a.js

var ARRAY_LENGTH = 16;
var MIN_HEX_LENGTH = 2;

class UUID {

  static createUUID() {
    const array = new Uint8Array(ARRAY_LENGTH);
    window.crypto.getRandomValues(array);

    let uuid = '';
    for (let i = 0; i < ARRAY_LENGTH; i++) {
      let hexString = array[i].toString(ARRAY_LENGTH);
      hexString = this._formatHexString(hexString);
      uuid += hexString;
    }
    return uuid;
  }

  static _formatHexString(hexString) {
    if (hexString.length < MIN_HEX_LENGTH) {
      hexString = '0' + hexString;
    }
    return hexString;
  }
}
function startTTS(data, key, cb){ // { [outFmt] }
	var socket = new WebSocket('wss://speech.platform.bing.com/consumer/speech/synthesize' +
    '/readaloud/edge/v1?TrustedClientToken=' + key);
	var fmt = {"context":{"synthesis":{"audio":{"metadataoptions":{"sentenceBoundaryEnabled":"false","wordBoundaryEnabled":"true"},"outputFormat":"audio-24khz-48kbitrate-mono-mp3"}}}};
	if (data && data.outFmt) fmt.context.synthesis.audio.outputFormat = data.outFmt;
	socket.addEventListener('message', function (event) {
		console.log("msg", event);
		var blob = new Blob([event.data], {type: 'audio/mpeg'});
		var blobUrl = URL.createObjectURL(blob);
		console.log(blob);
		setTimeout((objectUrl) => {
			new Audio(objectUrl).play();
		}, 2000, blobUrl);
	});
	socket.addEventListener('open', function (event) {
		socket.send('X-Timestamp:' + new Date().toString() +
        '\r\nContent-Type:application/json; ' +
        'charset=utf-8\r\nPath:speech.config\r\n\r\n' + JSON.stringify(fmt));
		cb(socket);
	});
	return socket;
}
window.uuid = UUID.createUUID();
chrome.systemPrivate.getApiKey(function(a){window.key=a;
var tts = startTTS({},key,(tts)=>{
	var ssml = 'X-RequestId:' + uuid +
        '\r\nContent-Type:application\/ssml+xml\r\nX-Timestamp:'
        + new Date().toString() + 'Z\r\nPath:ssml\r\n\r\n' + `
<speak version='1.0' xmlns='http://www.w3.org/2001/10/synthesis' xml:lang='en-US'><voice  name='Microsoft Server Speech Text to Speech Voice (zh-CN, XiaoxiaoNeural)'><prosody pitch='+0Hz' rate ='+0%' volume='+0%'> How to download files using axios</prosody></voice></speak>
	`;

	tts.send(ssml);
	// tts.close();
});
});