To duplicate a project between two distinct Dataiku instances, you can:
in the existing project, go to project home page → settings (or “project administration” for older DSS versions), then action → export the project. You get a .zip file, downloaded by your local browser.
on the second DSS instance, go to the home page of DSS (the list of project), click “Import project” (or new “project → import” for older versions) and upload this zip file.
The procedure is detailed in this article: https://www.dataiku.com/learn/guide/tips/duplicate-project.html