title: Error: "message": "Login Required" when use Youtube Analytics API
body: <p>I am working with youtube api. when I hit this url "<strong><a href="https://www.googleapis.com/youtube/analytics/v1/reports?ids=channel%3D%3DMINE&amp;start-date=2015-01-01&amp;end-date=2016-01-31&amp;metrics=likes%2Cdislikes&amp;key=" rel="noreferrer">https://www.googleapis.com/youtube/analytics/v1/reports?ids=channel%3D%3DMINE&amp;start-date=2015-01-01&amp;end-date=2016-01-31&amp;metrics=likes%2Cdislikes&amp;key=</a>{API Key}</strong>"</p>
  
  <p>it gives 401</p>
  
  <pre><code>{
   "error": {
    "errors": [
     {
      "domain": "global",
      "reason": "required",
      "message": "Login Required",
      "locationType": "header",
      "location": "Authorization"
     }
    ],
    "code": 401,
    "message": "Login Required"
   }
  }
  </code></pre>
  
  <p>but I hited in the explorer "<a href="https://developers.google.com/apis-explorer/" rel="noreferrer">https://developers.google.com/apis-explorer/</a>?"
  it working fine.<br>
  How do I make the first request work?</p>