Library file is located at /pub/js/FormBuilder.js
FormBuilder.JS is deployed at https://ancient-ridge-28623.herokuapp.com/
In your HTML file:
<script src="https://code.jquery.com/jquery-3.5.1.js" defer></script>
<script type="text/javascript" src="location/of/FormBuilder.js" defer></script>
Initialize FormBuilder before using it:
const formBuilder = new FormBuilder();