NextGEN Gallery Sell Photo

Hi, am so very new to WordPress and plugins. I am at Wealthy Affiliates with WP V4.1. I installed NextGEN Gallery Sell Photo and activated it. There are no updates so far as I can see. I am struggling with the following. I created a new page called Photograpy. I uploaded my photos using the WP Generic Add Media button which is in the page editor. The installation instructions require me to add the following shortcode: [nggallery id=”1″ template=”ngsellphoto”]. I did that in the text tab on the Photography page. I added my gallery of 5 images to the page and updated. In preview how, I see the photos, no buy now, and only the shortcode. Please can someone help me? Thanks in advance.