Are you sure that this is not just a quick example of how to set it up and you do not need to edit it to suit your own needs?
Finally, remember that to use it, you need to import it through the backend:
https://support.wix.com/en/article/corvid-managing-external-code-libraries-with-the-package-manager#using-an-installed-package241
Hope you can get it sorted out soon, or if it still doesn’t want to work, that somebody else can offer a better and correct fix to your issue.