Can't see Stacks elements in menu, only in add ons

Can anyone tell me how to add the add ons into a page? I’ve downloaded Blank 5.1 Theme from Themeflood, and Pro Styles and Button 2 from Big White Duck - BUT I cannot find a way of creating these menus - I see the add ons in the add-on folder, but I do not see them as Stacks elements that can be added to a page, what am I missing please? Tried dragging, clicking, double clicking, I’m lost!

Simon

Simon, check the videos on yourhead.com for Stacks Plugin usage.