jQuery function not running clone()

Hey guys I’m trying to implement the code here: https://stackoverflow.com/questions/50383369/creating-multiple-identical-elements-in-jquery/50383409#50383409

$('div').on('click', () => {
  $('ul').append($('ul > li:last-child').clone())

On my published site you can see nothing is happening like in the SO post. Is there something I need to be doing different for Webflow to handle this?

If you inspect the page at the URL here you will see my script and markup:

I not 100% sure, but i believe JS will stop working after error is fired. ( You have some jquery errors ).
Other than that I tried script and is working fine.