Pinboard Theme does not show featured image on any page

I set the featured image on any page, including my static home page and the image does not show up on the page, although the thumbnail does show up. I even tried it on a blank page and it still didn’t show up anywhere. How do I get the image to show up, and where is it supposed to show up? I would like for it to be in the Header under the name of my website (on the home page), or under the page name on other pages.