Right Sidebar: This sidebar area is displayed on the right side of the homepage, blog page, archive pages, single blog pages, 404 page, search page, and other pages.
Left Sidebar: This sidebar area is displayed on the left side of the homepage, blog page, archive pages, single blog pages, 404 page, search page, and other pages.
Above Footer Widgets Area: This sidebar is displayed just above the footer section of frontpage section.
If you want to add a widget area in the footer then you must add widgets in Footer Widget 1, Footer Widget 2, Footer Widget 3, and Footer Widget 4.