To setup the Veeam API Integration go to Integration -> Veeam Availability Console and click Configure new Source.
We recommend you create a user specific to Backup Radar for the integration and not use the default administrator account as shown. Name the profile, add the username and password and then setup the link to your Availability Console. The permissions on this user must be elevated, Veeam will not allow a read only user to pull backup data. Be sure to put :[port number] behind your link as this is a configurable setting and may differ from the default one you see below: