title: Call a Google Sheets add-on within a Google Apps Script?
body: <p>Is it possible to call a Google Sheets add-on as if it were a function in an Apps Script?</p>
  
  <p>I am trying to automate a few steps like this:</p>
  
  <ol>
  <li>Import/append data from sheet 1 to main sheet 1</li>
  <li>Import/append data from sheet 2 to main sheet 2</li>
  <li>Merge values/append new values from main sheets 1 and 2 into main sheet 3</li>
  </ol>
  
  <p>All of these steps are done with 2 add-ons. Ideally, I could call those add-on functions with a script and run the script with a button.</p>
  
  <p>Is this possible?</p>