429 error while using 0auth 2.0 playground

I am having a problem retrieving the accounts in 0auth 2.0 playground. After following the steps in the Google Business API's basic setup, 0auth 2.0 playground returns a 429 response code. So far, I have double checked that the google my business api is enabled, and then tried following the steps in the Google Profile API's basic setup again. I have requested a higher quota, but what might be causing this?

This seems like a duplicate of this SO issue. On that thread it looks like the summary of steps to resolve are:

• Request access to the API steps
  • Apply for access to the API
• Apply for a higher than 0 quota or via the project Quota section in console.cloud.google.com