Added by Damien Figuet about 6 years ago
It seems that only administrators can duplicate projects.
It would be usefull that Role given to a non-admin user who creates a project can also duplicate projects they already have access.
Around a year ago this feature (duplicating projects in admins dashboard) has been created here https://www.redmine.org/issues/886 so I think you can write there and might get feedback regarding this, at least that's what I did when needed some feature for my project.