How to use CDN with Smart Slider?
To use CDN on your website, you will have to set it up globally to make your whole website use your CDN address. You can see in this documentation, how it's done. You should clear the slider's cache after you made the necessary changes.
Open up your wp-config.php file, and change the WP_CONTENT_URL constant to the CDN url, which points to your wp-content folder:
Follow these instructions.
One possible way from our end
Our slider is using urls pointing to your website, so if you want to change all urls to your CDN url, use the translate url option, which can replace all urls used by us to any url you give.