Как получить крошечный URL-адрес прямой трансляции с помощью YouTube Data API v3

function authenticate() {
    return gapi.auth2.getAuthInstance()
        .signIn({scope: "https://www.googleapis.com/auth/youtube.readonly"})
        .then(function() { console.log("Sign-in successful"); },
              function(err) { console.error("Error signing in", err); });
  }
  function loadClient() {
    gapi.client.setApiKey("YOUR_API_KEY");
    return gapi.client.load("https://www.googleapis.com/discovery/v1/apis/youtube/v3/rest")
        .then(function() { console.log("GAPI client loaded for API"); },
              function(err) { console.error("Error loading GAPI client for API", err); });
  }
  // Make sure the client is loaded and sign-in is complete before calling this method.
  function execute() {
    return gapi.client.youtube.liveStreams.list({
      "part": [
        "snippet,cdn,contentDetails,status"
        //"cdn"
      ],
      "mine": true
    })
        .then(function(response) {
                // Handle the results here (response.result has the parsed body).
                console.log("Response", response);
                
                var responseData = JSON.stringify(response);
                alert(responseData);
                
                //alert(response.result.items);
                
                var itemsArr = response.result.items;
                var itemObj = itemsArr[0];
                alert('streamName = ' + itemObj.cdn.ingestionInfo.streamName);
                
                //alert(responseData.result);
                //var result = responseData.result;
                
              },
              function(err) { console.error("Execute error", err); });
  }
  gapi.load("client:auth2", function() {
    gapi.auth2.init({client_id: "YOUR_CLIENT_ID"});
  });

<script src="https://apis.google.com/js/api.js"></script>
<button onclick="authenticate().then(loadClient)">authorize and load</button>
<button onclick="execute()">execute</button>