Gallery not displaying

I installed the NextGen gallery. Added a gallery. Went to the page I want to add the gallery. Clicked on the button to add the gallery. Selected the gallery I wanted to add. Updated the page. And when I viewed the page, the gallery is not there. It shows something that looks similiar to the code the buttom created. I need help getting the gallery to appear on the page after it is updated.

https://www.ads-software.com/extend/plugins/nextgen-gallery/