title: Getting the video thumbnail of private videos on Vimeo
body: <p>This is a repost from the vimeo forum, but since nobody is answering over there, I try my luck here:</p>
  
  <p>I have been trying for some hours now to get my head around the whole oAuth thing, but I don't seem to get it working. I want to retrieve thumbnails for private videos, using the <a href="https://developer.vimeo.com/apis/advanced" rel="noreferrer">advanced vimeo api</a>. This is what I have right now:</p>
  
  <pre><code>$vimeo = new phpVimeo($consumer_key, $consumer_secret, $access_token, $access_token_secret);
  $result = $vimeo-&gt;call('vimeo.videos.getThumbnailUrls', array('video_id ' =&gt; $video_id));
  </code></pre>
  
  <p>When I try it like this, I keep getting the error</p>
  
  <pre><code>"Fatal error: Uncaught exception 'VimeoAPIException' with message 'Invalid signature' ".
  </code></pre>
  
  <p>I'm absolutely positive that the keys and secrets are correct. Do I have to do more to make this thing work? Of course, it would be amazing to have an example where I just have to put in all my key data in and it works.</p>
  
  <p>thanks in advance!</p>