如何从谷歌获取Access_token？

Question

我在打电话：

• URL - https://accounts.google.com/o/oauth2/token
• METHOD-POST

• BODY -

  {
     "client_id": "832123433433-9r28oattkl7rbaa5fsp3stfmhcvvlolf.apps.googleusercontent.com",
     "redirect_uri"  : "https://www.inka.com/oauth2callback",
     "client_secret"  :"XXXXXXXXXXXXXXXXXX",
     "grant_type" : "authorization_code"
  }

显示以下错误

{
    "error": "invalid_request",
    "error_description": "Required parameter is missing: grant_type"
}

任何人都可以告诉我哪里错了吗？