title: Google OAuth 2 authorization - Error: redirect_uri_mismatch
body: <p>On the website <a href="https://code.google.com/apis/console">https://code.google.com/apis/console</a> I have registered my application, set up generated <strong>Client ID:</strong> and <strong>Client Secret</strong> to my app and tried to log in with Google.
  Unfortunately, I got the error message:</p>
  
  <pre><code>Error: redirect_uri_mismatch
  The redirect URI in the request: http://127.0.0.1:3000/auth/google_oauth2/callback did not match a registered redirect URI
  
  scope=https://www.googleapis.com/auth/userinfo.profile https://www.googleapis.com/auth/userinfo.email
  response_type=code
  redirect_uri=http://127.0.0.1:3000/auth/google_oauth2/callback
  access_type=offline
  approval_prompt=force
  client_id=generated_id
  </code></pre>
  
  <p>What does mean this message, and how can I fix it?
  I use the gem <strong>omniauth-google-oauth2</strong>.</p>