Duplicating projects directly from the Cloud Dashboard is not possible right now. We are working on this functionality and it will be available in the future.
What you can do to duplicate projects is to save individual pages in the builder, add a new project and recreate your pages from the saved layouts.
(Not ideal as it requires some leg work from you, especially if you have a multi page project, but this is the way to do it until we bring in the duplicate project feature.)
Here is a short reminder on how to save and access layouts in Brizy:
Step 1. Save any layout from the bottom right hand side near the Update button.
Step 2. Access your saved layouts from the Saved tab when adding a new block on the page.
All saved layouts (and blocks) are accessible in any project (and across sub accounts), existing or new so you can easily use them to duplicate projects.