Please check out our Live Demo to get an idea about how JSFiddle for Confluence works.
As any app for Confluence Cloud, you can install the app via the Confluence admin menu.
Log into your Confluence instance as an admin.
Click on “Apps > Manage apps” in the header menu.
Click on “Find new apps” on the right navigation.
Search for “JSFiddle for Confluence” and select it.
Click on “Try it free” to install the app.
On a Confluence Page, click the “Insert” / “+” Button.
Search for “JSFiddle” and select the appropriate macro.
Change the macros settings appropriately and click “Insert”.