JS not loading

Hello there! I just purchased 2 different themes on Envato. The installation worked perfectly (using ThemeRex Theme Panel). But when I check the websites, all JS can’t be loaded (while all the files are present on the server). The console shows error messages for all js files:

jquery.min.js:1 Failed to load resource: net::ERR_NAME_NOT_RESOLVED
jquery-migrate.min.js:1 Failed to load resource: net::ERR_NAME_NOT_RESOLVED
wp-polyfill-inert.min.js:1 Failed to load resource: net::ERR_NAME_NOT_RESOLVED

Here is the website URL: https://cuveedefernelmont.be/

Could someone help me with this?