Copy an Epic with all child work items

You can duplicate an epic with a new title by the following steps:
1- Open backlog
2- Open the epic you want to duplicate
3- Click on the three dots on the right upper corner
4- Choose "Create a copy of work item"
5- Check "include child work items"
6- Apply and refresh page

Please note that this only copies one level under the epic.
Let's say you have epic -> feature -> requirement, it will only copy the epic and features inside it, without including the requirements