GASでNiconicoのランキング取得

function test(){
  console.log(niconicoRankig("VOCALOID"));
}


const Webhook_URL = "https://snapshot.search.nicovideo.jp/api/v2/snapshot/video/contents/search";

function niconicoRankig(Search_Word) {
  let params =
  {
    q: Search_Word,
    targets: "tagsExact",
    //タグで完全一致検索
    fields: "contentId",
    _sort: "-viewCounter",
    //視聴回数でソート
    _limit: 1,
    _context: "アプリ名、メールアドレス、NiconicoのID",

  };

  let queryString = Object.keys(params)
    .map(key => encodeURIComponent(key) + "=" + encodeURIComponent(params[key]))
    .join("&");

  let requestUrl = Webhook_URL + "?" + queryString;
  let options = {
    "method": "get",
    "headers": {
      "User-Agent": "アプリ名、メールアドレス、NiconicoのID"
    },
  };
  var response = UrlFetchApp.fetch(requestUrl, options);
  var json=JSON.parse(response.getContentText());
  const video_URL="https://www.nicovideo.jp/watch/"+json.data[0].contentId;
  return video_URL;
}