When on a Foundry Branch it is not possible to duplicate the workshop on the branch per the docs:
Duplicating modules on a branch is not currently a supported feature. We are tracking this now though.
In the meantime you can duplicate the module on main and add it to your branch if you would like, however any modifications you have made on your branch will not be present.
To better understand the need can you describe the work that you are trying to do and why you ran into needing this feature? Thanks in advance!
I ran into this problem when trying to strip out some changes I’d made on a branch into an entirely separate module.
In the end I worked around this by using the copy/paste functionality (though that seems to have it’s own problems - many component names get dropped, additional ‘add section’ areas appear).