For your website set up CDN, static resources need to be placed into your CDN website.
The official built-in themes of static resources:
After set up your cdn, you should keep the assets/dist directory. Which means if your cdn address is https://xxxx-cdn.xxxx.com. Then the resource request url is like: https://xxxx-cdn.xxxx.com/assets/dist/css/..../xxxx.css
To take effect also need to set in the global configuration: asset_url items.