解决"Access Not Configured. The API (YouTube Analytics API) is not enabled for your project."

在用Google Developers OAuth 2.0 Playground试用Google YoutubeAnalytics API时总是返回下列403 Forbidden错误:

{
  "code" : 403,
  "errors" : [ {
    "domain" : "usageLimits",
    "message" : "Access Not Configured. The API (YouTube Analytics API) is not enabled for your project. Please use the Google Developers Console to update your configuration.",
    "reason" : "accessNotConfigured",
    "extendedHelp" : "https://console.developers.google.com"
  } ],
  "message" : "Access Not Configured. The API (YouTube Analytics API) is not enabled for your project. Please use the Google Developers Console to update your configuration."
}

在https://console.developers.google.com查看我的项目，各种可能需要的API都激活了：

Analytics API
BigQuery API
Cloud Debugger API
Contacts API
Debuglet Controller API
Google Cloud Logging API
Google Cloud SQL
Google Cloud Storage
Google Cloud Storage JSON API
Google+ API
Google+ Domains API
YouTube Analytics API
YouTube Data API v3
YouTube Reporting API

最后的解决过程如下：

创建一个web应用证书，关键是其redirectURI为https://developers.google.com/oauthplayground。
关键的一点是在Google Developers OAuth 2.0 Playground中采用**“Use yourown OAuthcredentials”**。我觉得403错误可能是playground自动创建的证书没有和自己的项目绑定，因此认为YoutubeAnalytics API没有激活。
200OK出来了，搞定：

当然，类似查询也可以在Google API Explorer里面完成，而且没碰到什么障碍。