How to add custom widgets (noUiSlider)

Hi there,
thanks for the plugin, appreciate your work! I need a range slider from the custom widgets (https://surveyjs.io/Examples/Survey-Creator/?id=customwidgets&theme=bootstrap) and I’m not quite sure how to get there. It says “all you need to do is to include the third-party library scripts and our custom widget scripts on your web page”, sounds easy enough, but where am I supposed to implement that in WordPress? If I poke around in the plugin, it will eventually be overwritten.

If I get this right, those two js files need to be loaded when the editor and the frontend loads up, right?
<script src="https://unpkg.com/[email protected]/distribute/nouislider.js"></script>
<script src="https://surveyjs.azureedge.net/1.5.17/surveyjs-widgets.js"></script>

Best regards