How do I add widgets on full screen dashboard

Hi All

I have a dashboard that has 3 pages, I have the menu bars hidden so full screen, I have added a widget onto the 3rd page and now I have no option to edit dashboard. how do I get round this, any ideas would be greatly received.

@stevepage64 Dashboard edit button is also shown in Navigation Drawer (swipe from left screen edge) next to the selected dashboard name.