title: Setting up oAuth with the Google AdWords API
body: <p>I am attempting to get get a Ruby on Rails project that uses the Google AdWords API.</p>
  
  <p>What I did so far, following the steps in <a href="https://developers.google.com/adwords/api/docs/guides/first-api-call?hl=nl#set_up_oauth2_authentication" rel="nofollow noreferrer">this guide</a>:</p>
  
  <ul>
  <li>I created an AdWords Manager account.</li>
  <li>I created a test account that is part of the AdWords Manager account.</li>
  <li>I set up the Ruby client library in my Rails project.</li>
  <li>I then attempted to set up OAuth2 authentication with the <a href="https://github.com/googleads/google-api-ads-ruby/blob/master/adwords_api/examples/v201702/basic_operations/get_campaigns.rb" rel="nofollow noreferrer">example code</a> from the guide.</li>
  </ul>
  
  <p>However since the guide was written (and the <a href="https://www.youtube.com/watch?v=yaDlZMfYWkg" rel="nofollow noreferrer">video version</a> of the guide was made) it seems that the interface has changed. I am able to create a Client ID <code>client_secrets.json</code>-file, or a Service Account .json file. I am able to export these and read the settings from .</p>
  
  <ul>
  <li>I added the required settings, using an <code>OAUTH2_SERVICE_ACCOUNT</code> .json file.</li>
  </ul>
  
  <p>Now, when attempting to connect, I get back the AdwordsAPIException <code>AuthenticationError.NOT_ADS_USER</code>.</p>
  
  <p>I therefore know that the actual <em>authentication</em> works. However, the <em>authorization</em> does  not.</p>
  
  <p>How can I turn on AdWords API support for the oAuth credentials from my google accounts? The Google Credentials Console lists many APIs that you can turn on, but the AdWords API is not in there. The <a href="https://developers.google.com/adwords/api/docs/guides/first-api-call?hl=nl#set_up_oauth2_authentication" rel="nofollow noreferrer">AdWords guide</a> does not mention turning on an API at all, and only tells you to create a new Credential.</p>
  
  <p>What is going on here?</p>