在Go中连接Google Calendar API的凭据

I am converting a PHP application to access Google calendar to Go. I used this step by step to get started.

All went smoothly, but when I run quickstart.go, I get the following error:

Unable to parse client secret file to config: oauth2/google: missing redirect URL in the client_credentials.json exit status 1

Content of the client_secret.json is:

{  
   "installed":{  
      "client_id":"***********content.com",
      "project_id":"*******",
      "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"
   }
}

That client_secret.json file is located at the root of my GOPATH as instructed in the step by step

I already have aOAuth 2.0 client ID for my PHP app that works just fine in PHP. I just want to use that one in the a new Go application to access multiple user calendars, but when I download the json file attached to that ID, I am getting the error above. Maybe the quickstart.go is not meant for that usage.

Any hints?