Drag and Drop Areas
The dnd_area syntax that supports the new drag-and-drop page editing experience is out of beta and available to all accounts! Drag and drop areas represent the future of how marketer-friendly websites are built on the HubSpot CMS, while allowing developers to utilize coded files, and the tools and technologies they prefer. To get started building using drag and drop areas, follow the getting started guide. You can can check out the #hs-cms-boilerplate templates, which utilize this syntax. As always, please send any feedback along in #drag-n-drop-pages In our Developer Slack.
To be clear though need to be added through code. A template needs to be built with a drag and drop area inside of it.
Flex columns and drag and drop areas are different concepts, though similar. Flexible columns offer the ability to place and re-arrange modules in a vertical manner. Drag and drop areas similarly allow placing and re-arranging modules but they are not limited to one direction, you can place modules side by side, contain them in sections and more.