How to duplicate a markup
Find the markup that you want to duplicate in the Layer manager in the right-hand toolbar. You can do this by:
Clicking on the markup which will open the Layer manager at the correct location; or
Open the Layer manager from the right-hand toolbar and select the Markups tab:
The option to "Duplicate" can be found in the three-dot menu of any markup. Note: you can duplicate any markup, whether you created the original or not.
A new markup will appear offset from your original markup. If you want to move it, click on the markup to enter the markup edit state.