No you don’t need a license or any other plugin in order to make Epik work. That video you’re talking about wasn’t created by Appfinite, that is a 3rd party plugin that someone made, but you don’t need it for Epik.
The tutorials to get Epik setup and working are located at the top of the Epik Forum page here – https://appfinite.com/forum/epik-theme-support/
You can use this link in order to import all the widget content from the Epik demo automatically – https://appfinite.com/topic/easy-way-to-setup-the-epik-homepage-in-one-click/ …you can add them in manually if you want to, there are tutorials that help with that.