获取私人YouTube视频详情

I want to get a logged in user's private YouTube video details using the v3 API. I have already extended my Google Oauth authentication with YouTube scope. The login process was success. The owner of the private video is the logged in user.

However if I use the following request I got a valid success message but with a 0 result.

My request:

https://www.googleapis.com/youtube/v3/videos?part=contentDetails,snippet&id=VIDEO_ID&key=API_KEY

Response:

{
    "kind": "youtube#videoListResponse",
    "etag": "\"xxxxxxxxxxxxxxxxxxxxxxxxxxxxx\"",
    "pageInfo": {
    "totalResults": 0,
    "resultsPerPage": 0
},
    "items": []
}

Any idea what can be the problem?

Finally I have found the problem. The Google OAuth access token was not part of the request header. After including it in the request the response gave me the correct result.