Hi Guys i'm at the last step of this project, i've saved my Canvas image on server side and was hoping to now be able to change the share thumbnail for Facebook. Below is the code up to the sharing part.

```
jQuery(document).ready(function($){
//Share the current Canvas Image to Facebook
jQuery(document).on('click','#poster',function(e){
  e.preventDefault();
  /*Save to server*/
  var canvas = document.getElementById("c");
  var imageData = canvas.toDataURL("image/png");
  $.ajax({
  type: "POST",
  url: rkax.ajaxurl,
  data: { 
         action: 'raketrad_save_to_server',
         imgBase64: imageData
  }
}).done(function(img_url) {
  console.log(img_url);
 $('body').append('<meta property="og:image" content="'+img_url+'" />');
 FB.ui({
        method: 'share',
        href: window.location.href,
      }, function(response){});

}); 

```

I am finding that even when the meta property has been appended to the page. Facebook still takes the default URL. How do i go about chaning this?