Enter a reference name for your account and enter the API key found in your Bing Webmaster Tools interface.
Select the account in the list, select a default web site from the drop down at the bottom, then click the Make Default button to establish a default account.
The default account can be changed in an Analytics Edge Core macro by opening the Accounts wizard while a macro is open in the Task Pane. Select the new account and click Save Default in Macro button.