问如何异步加载facebook sdk

EN

<div id="fb-root"></div>
<script>
window.fbAsyncInit = function() {
  FB.init({
  appId                : "1549906631990069",
  status               : true, 
  cookie               : true, 
  xfbml                : true, 

  oauth: true,
  frictionlessRequests : true
});
};

(function(d, s, id) {
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) return;

js = d.createElement(s); js.id = id;
js.src = "//connect.facebook.net/en_US/all.js";
fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));

</script>

<script type="text/javascript">
function shareOnFacebook() {
    var $temp = $(".wpProQuiz_points").find("span");
                    var scored = $temp.eq(2).text();

  FB.ui(
  {
    method        : 'feed',
    display       : 'iframe',
    name          : 'I have Scored '+ scored + ' in edumongoose quiz.',
    link          : 'https://quiz.dev.edumongoose.com'
  },
  function(response) {
    if (response && response.post_id) {
      alert('OK! User has published on Facebook.');

    } else {
      alert('Post was not published.');
    }
  }
);