Google Fonts Developer API Key
Because the Font Manager taps into the Google Font API in order to get access to all the Google fonts, you’ll need to get a Google Fonts Developer API Key when using the Genesis Design Pro - Google Web Fonts add-on.
In Design Palette under Settings there is a direct link to the Google Developer API page.
On the Google Developer API site, find the button that says Get Key. It will ask you to name your project, and this can be anything you want. After you name your project, a pop-up will have your Google API key. Copy the key and add to the Google Fonts API Key box in Design Palette Pro.