Setting up a clipboard.js button

I'd like to have a button that matches the others on my site template (small, left aligned), but instead of linking to another page, I'd like this button to copy a piece of text to the clipboard.

Enter clipboard.js. I believe I've uploaded the javascript properly - as a "file" link under unlinked pages). Under header code injection I've configured:

<!-- Plugin Clipboard.js -->
<script src="mydomain.net/clipboard.min.js">
</script>
<!-- end Plugin Clipboard.js -->

But I'm lost on how to actually get it working using a squarespace-styled button.

Your advice is greatly appreciated!