Enter the Bing maps license in the GlobalConfig.xml file, and then load it in the database.
Please find the info on getting a key is at:
http://msdn.microsoft.com/en-us/library/ff428642.aspx
Bing Maps Account Center http://www.bingmapsportal.com/
Replace the value in GlobalConfig with the key obtainded from Bing Maps Account Center during the site installation.
IMPORTANT: To make these changes available to the GN4 users, after you saved the GLOBALCONFIG.XML file and imported it into the database, or after you modified it in EdAdmin4 and saved, recycle the GN4 application pools on all IIS servers and then make all users log out and log back in.