How to add SSA buttons below widgets on Twenty Twelve front page

I am using the Twenty Twelve theme with a static front page with 3 widgets in the “secondary widget area” of the front page. This widget area appears below the main content, not in a sidebar or footer.

When I add the Simple Share buttons to the Home page, they appear between the main content and the widgets. But I want the buttons to display BELOW the widget area, just before the footer on this page.

I deselected Home and then added [SSBA] in the front-page.php template just before the footer, but what shows there is “[SSBA]”, not the actual buttons. Can you please point me in the direction of an explanation of how to use this shortcode correctly?

Here is the site (in progress): https://travel-ariela.com/sept14wp/index.php

Thanks,
Susan

https://www.ads-software.com/plugins/simple-share-buttons-adder/