Map & Directions error

For no reason that I have been able to detect my “The Blue Shamrock Pub Map and Directions” link displays the following error message: For Development Purposes – This page cannot load Google Maps”. Page link: http://theblueshamrockpub.com. I’m guessing the problem might be a Google Maps API key but I cannot find the place to correct it in the theme settings. Can you provide a solution to both issues: 1) why is the page not working; 2) where and how to obtain an insert an API key if that is the issue. Thank you.