This is a Contao CMS extension. It is only in use for the back end. This extension give you the opportunity to preselect content elements for each layout section. So a editor can only add those content elements you want him to add in a special section.
This extension is not created as a right management for content elements. It help's designer to force an editor to use the content elements for what they are created: To create a beautiful web page.
You can use ce_section in a current running installation. You need a Theme and some Layouts.
Create a section and choose the content elements you want to enable for this section.
Just navigate to an article with the created section name from above and create a content element. You only see the content element you have allowed.