Are you looking to clone all of the data in the project, or just create a new project with the same setup as the original?
If it's the latter, when you create your new project, check the Share Settings with Existing Project box and then choose the project to share settings with. This truly does make the configuration shared, which means if you change a screen or workflow in one project, it will also change in the other.
As to cloning the setup AND data, as far as I know there's no easy way to do that yet. There are a number of add-ons that will let you clone all project data from one project to another; read the full post here (not just the accepted answer) for more. That post is a few years old, though, and it's possible there are other options now.
@Celine Penaredondo there's been a change to the UI of creating projects. You can still create a project with shared configurations, but you do need to choose a template to start with - it doesn't really matter which one, since you'll choose to share an existing project's configuration later on. You just need to make sure to choose a project of the right type (Software vs Work Management vs Service Management if you have all three products) and the correct management type (company managed - formerly called Classic - or team managed - formerly next-gen.)
It would definitely be easier if they had the "share with existing project" first, so you could just do that and skip all the rest of the options, but as of now this is what the process looks like:
It's the final screen where you can check the "share settings with existing project" box and select the project to "clone".
If you want to bulk clone and move all issues from one project to another you can try out our Marketplace app Deep Clone for Jira.
Update: It's now also possible to clone entire company-managed projects, including issues, components and versions.
Don't hesitate to get in touch with our support if you have questions or feedback.
Hi Estanis - Welcome to the Atlassian Community!
You can't really clone a project per se. When you create a Classic Software project, you can base it on an existing Classic Software Project. That will clone the connections to shared schemes.
It will not copy or clone the issues on the original project though.
And you cannot perform this function on Jira Service Desk or Next-gen projects.
@Estanis - no, next-gen projects are not available for shared configurations. That's one of the limitations, and why many companies don't use them. They're nice for small companies that want one-off projects that are quick to set up but don't need any customization, but they're completely standalone.