You need to upload these two files to some storage area, like dropbox or something and link to these files in the custom script like:
Change your-storage-url to the url pointing to these files you have saved somehwere. Webflow does not support uploading of js files currently, so you need an external storage for these. There might be some public cdns that also have these files somewhere, you can search for those on the internet.
Here is the example site I made from the CodePen:
So yes, it can be done, but with some custom coding that you need to manage/support yourself. You can always ask questions on the forum though
Here is a video, which also might help you to get this going on your site
I hope that helps, cheers ! Dave