You need the following information to link your account: Consumer key, Consumer secret, OAuth Realm, UID and Ad Unit ID.
Consumer key and Consumer Secret: You have to request both from Openx support team.
OAuth Realm: Information provided by Openx: “The realm value is a string, generally assigned by the origin server. The realm parameter allows the protected resources on a server to be partitioned. For example, OAuth realm="http://server.example.com/".
UID: In your Dashboard go to Inventory tab and proceed to Ad Units. UID is located in the upper part of the page next to Legacy ID.
Ad Unit ID: Click on an Ad Unit you need and you’ll get to Ad Tags page. Ad Unit ID is under “Integrate using SDK.”