Google+ Playground api not working

Question

I'm using Google Playground for accessing Google+ APIs. When I try to call the API

 https://www.googleapis.com/plusDomains/v1/people/[user_id]/circles

..then it results in error:

{
  "error": {
    "code": 403, 
    "message": "Access Not Configured. Please use Google Developers Console to activate the API for your project.", 
    "errors": [
      {
        "domain": "usageLimits", 
        "message": "Access Not Configured. Please use Google Developers Console to activate the API for your project.", 
        "reason": "accessNotConfigured"
      }
    ]
  }
}

In step 1 on the playground page, I've selected both the 'Google+ Domain API' and 'Google+ API v1' and authorized and got the access tokens. Of course, [user_id] is replaced properly before making the API call.

Answer 1

Found out the reason. The Google+ Domain APIs are not meant to be accessed without having a domain account configured on Google. After setting the domain account on Google, the administrator needs to set the permissions to allow the access to these APIs.

https://developers.google.com/+/domains/