@jarens I've been trying all morning to get chart.js in via

<script src="<https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.7.3/Chart.min.js>"></script>

but have had 0 luck

I had the same issue with a portlet. I edited the lib to remove the AMD portion because it was time sensitive (public bundle), but @michoel posted something that works.

var oldDefine = window.define;
        window.define = null;
        jQuery.getScript("<https://code.jquery.com/ui/1.12.1/jquery-ui.min.js>", function (result) {
            window.define = oldDefine;
        });