Oauth 2.0 用于在erlang中访问google api的Oauth2

您好，我正在为oauth2协议编写代码，用于访问google pub/sub api。我的代码如下

方法=员额

URL = "https://www.googleapis.com/oauth2/v1/userinfo",
Grant = "grant_type=authorization_code:params:oauth:grant-type:jwt-bearer&assertion=&
        assertion=JWT_Token ",

Header = [{"Content-Type","application/x-www-form-urlencoded"}],
Body = [Grant],
Type = "application/x-www-form-urlencoded",
Options = [],
httpc:request(Method, {URL, Header, Type, Body}, [], Options).

我在发送http请求时遇到以下错误

Response{ok,{{"HTTP/1.1",404,"Not Found"},
          [{"cache-control",
            "no-cache, no-store, max-age=0, must-revalidate"},
           {"date","Tue, 10 Nov 2015 22:27:36 GMT"},
           {"pragma","no-cache"},
           {"accept-ranges","none"},
           {"server","GSE"},
           {"vary","X-Origin"},
           {"content-length","9"},
           {"content-type","text/html; charset=UTF-8"},
           {"expires","Fri, 01 Jan 1990 00:00:00 GMT"},
           {"x-content-type-options","nosniff"},
           {"x-frame-options","SAMEORIGIN"},
           {"x-xss-protection","1; mode=block"},
           {"alternate-protocol","443:quic,p=1"},
           {"alt-svc","quic=\":443\"; p=\"1\"; ma=604800"}],
          "Not Found"}} 

我几乎可以肯定我发送的授权值是不正确的。 我不确定要在URL和主机参数中传递什么参数。 请帮忙