Impossible to use this SDK is it possible that its unstable SDK?

问题

According to the documentation, I followed everything correctly, but I keep getting this following error:

<!doctype html>
<html>
<head>
  <title>My Skype Web SDK app</title>
  <script src="https://swx.cdn.skype.com/shared/v/1.2.15/SkypeBootstrap.min.js"></script>
</head>
<body>
  <script>
    Skype.initialize({ apiKey: 'a42fcebd-5b43-4b89-a065-74450fb91255' }, api => {
      var app = new api.application;
      app.signInManager.signIn ({
        username: 'sdfsfsfdsfsdf', //USE VALID username
        password: 'xxx'  // USE VALID password
      }).then(() => {
        console.log("signed in as", app.personsAndGroupsManager.mePerson.displayName());
      }, err => {
        console.log("cannot sign in", err);
      });
    }, err => {
      console.log("cannot load the sdk package", err);
    });
  </script>
</body>
</html>