After create the CDN resources (here) , the CDN resources now is ready to use.
If the website is a Joomla, there is Extension can use. One of them is CDN for Joomla (Free Version)
1) Log into Joomla admin portal
2) Go to Extension the Manage, follow by install
3) Under "Upload & Install Joomla Extension" , browse the zip package that downloaded from CDN for Joomla (Free Version) then click on Upload and install
4) Go to Extension the Manage, follow by Plugins
5) Click on the CDN for Joomla plugin
6) Fill in the CDN resources that create then save it.