If you open the Pages sidebar in the editor, select the page you want to duplicate, and click the three dots (…) next to the page name, one of the options on the menu that appears is ‘Duplicate’.
Or am I misunderstanding your question?
If you open the Pages sidebar in the editor, select the page you want to duplicate, and click the three dots (…) next to the page name, one of the options on the menu that appears is ‘Duplicate’.
Or am I misunderstanding your question?