show list voice and speak vietnamese

speech viet.js

var langList = document.getElementById('langList');
if ('speechSynthesis' in window) {
    // Start an html table for languages details
	var text = '<table border=1><tr><th>Default<th>Language<th>Local<th>Name<th>URI</tr>';
	// Get voices; add to table markup
	function loadVoices() {
		var voices = speechSynthesis.getVoices();
		voices.forEach(function(voice, i) {
          // Add all details to table
          text += '<tr><td>' + voice.default + '<td>'
              + voice.lang + '<td>' + voice.localService
              + '<td>' + voice.name + '<td>' + voice.voiceURI;
        });
	}
	loadVoices();
	langList.innerHTML = text;
	// Chrome loads voices asynchronously.
	window.speechSynthesis.onvoiceschanged = function(e) {
		loadVoices();
		langList.innerHTML = text;
	}
}

var lang = 'vi-VN'
var msg = new SpeechSynthesisUtterance();
var voices = window.speechSynthesis.getVoices();
msg.voice = voices.filter(voice => voice.lang == lang)[0];
msg.text = 'Hệ thống đã khởi động, chào mừng Hiệp quay trở lại';
msg.lang = lang;
window.speechSynthesis.speak(msg);

It is not working right now!

var msg = new SpeechSynthesisUtterance();
msg.lang = "vi-VN"; 
msg.text = "Xin Chào, tôi là Tâm";
speechSynthesis.speak(msg); 

This is awesome tutorial.
I would appreciate if daothithientamn or some experts will show an working example of an HTML file using Javascript with selected voice "vi-VN".
Thank you.