Google幻灯片api，jwt令牌

Question

我正在尝试实施Google server to server authentication using oAuth 为此我根据提到的步骤生成凭据，谷歌给了我json文件以下详细信息

  // this is sample data not real data
  {
    "type": "service_account",
    "project_id": "myapp",
    "private_key_id": "17af28d89ef88g59e9c44a51csf00f894c23",
    "private_key": "-----BEGIN PRIVATE KEY-----\nMIIEvgIBADANBgkqhkiG9w0BAQEFAASCBKgwggSkAgEAAoIBAQCYTyEAeQxHUP66[OTHER TEXT REMOVED]n-----END PRIVATE KEY-----\n",
    "client_email": "someemailname@projectname.iam.gserviceaccount.com",
    "client_id": "3246344567234535",
    "auth_uri": "https://accounts.google.com/o/oauth2/auth",
    "token_uri": "https://accounts.google.com/o/oauth2/token",
    "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
    "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/meshpresentations%40meshslides.iam.gserviceaccount.com"
  }

我在jwt.io中使用了“private_key”，如下图所示，但显示“无效签名”，是因为只有提供私钥（google）的服务器才能验证它是否是有效令牌？如果是这样的话，当我发起卷曲调用时，我会收到另一个错误。

{
   “error”: “invalid_grant”,
   “error_description”: “Invalid JWT: Token must be a short-lived token and in a reasonable timeframe”
}

我缺少什么？我甚至不确定我是否错误地制作了JWT令牌或者是否存在其他问题。 PS：我是学习者。

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