title: Issue: Google Apps Script Execution API
body: <p>I am an absolute beginner of web development and would like to use Google Apps Script Execution for my project.</p>
  
  <p>So I followed the documentation in </p>
  
  <pre><code>https://developers.google.com/apps-script/guides/rest/quickstart/php.
  </code></pre>
  
  <p>However, I am currently struggling the error </p>
  
  <blockquote>
    <p>"caught exception: Error calling POST
    <a href="https://script.googleapis.com/v1/scripts/" rel="nofollow">https://script.googleapis.com/v1/scripts/</a>{I put myscriptId here}:run:
    (403) The caller does not have permission"</p>
  </blockquote>
  
  <p>I have looked for the answer to solve the issue for a long time, but I haven't even gotten a clue. Has anyone ever followed the same documentation as me and had the same problem? If you have, could you let me know how to solve this?</p>
  
  <p>English is not my first language, so if this post does not make sense or you need more information, let me know as well.
  Any advice would be appreciated! Thanks in advance!</p>