title: Embed video in wordpress not showing
body: <p>I'm using the theme WPLMS to sell courses.</p>
  
  <p>Said that, I'm trying to embed the first video of the course on the course description page, so anyone can see it.
  I've placed the URL of the vimeo video inside a custom field of the wordpress and in the PHP file, instead calling the course picture, I'm calling to display the video: </p>
  
  <p><code>&lt;iframe src="&lt;?php echo esc_url( get_post_meta( get_the_ID(), 'primeiro_video', true ) ); ?&gt;" width="640" height="360" frameborder="0" webkitallowfullscreen mozallowfullscreen allowfullscreen&gt;&lt;/iframe&gt;</code>.</p>
  
  <p>The thing is that only a white space appears where the video was supposed to be and when opening the browser's inspector I see that the <code>iframe</code> tag is there but there is nothing inside.</p>
  
  <pre><code>&lt;iframe src="https://vimeo.com/51589652?api=1" width="640" height="360" frameborder="0" webkitallowfullscreen="" mozallowfullscreen="" allowfullscreen=""&gt;
    #document
      &lt;html&gt;
        &lt;head&gt;&lt;/head&gt;
        &lt;body&gt;&lt;/body&gt;
      &lt;/html&gt;
  &lt;/iframe&gt;
  </code></pre>
  
  <p>Any thoughts? Cheers!</p>