title: Google Cloud Text-to-Speech API - permission error
body: <p>I am attempting to set up Google Cloud Text-to-Speech API following these instructions - <a href="https://cloud.google.com/text-to-speech/docs/quickstart" rel="nofollow noreferrer">https://cloud.google.com/text-to-speech/docs/quickstart</a>
  I have successfully followed steps 1-6 for setting up Google SDK and authenticating with service account credentials.
  However, when I attempt to run the sample HTTP request for synthesising speech I receive the following error:</p>
  
  <blockquote>
    <p>Cloud Text-to-Speech API has not been used in project usable-auth-library before or it is disabled. Enable it by visiting <a href="https://console.developers.google.com/apis/api/texttospeech.googleapis.com/overview?project=usable-auth-library" rel="nofollow noreferrer">https://console.developers.google.com/apis/api/texttospeech.googleapis.com/overview?project=usable-auth-library</a> then retry.</p>
  </blockquote>
  
  <p>When following the link in the error message it leads to the following page:</p>
  
  <blockquote>
    <p>The API "texttospeech.googleapis.com" doesn't exist or you don't have permission to access it.</p>
  </blockquote>
  
  <p>I am grateful for help.</p>