slightly confused to be honest to your intentions here.
You would look to embed a form when you wanted that form to present to the users as they visted your page.
Where here it seems you want to have a button (or drop down later) that users click/select and then that is to present them a form, then embedding doesn’t come into this, nor the util.js
All you should need under your ‘button’ is the link to the actual form and that then opens the form for them.
No reason though why you couldn’t set up a number of pages in your website and embed each of the forms to these pages and then your button/drop down is simply sending them to that webpage for them to see the form