Can I pass the callback url when I try to auth?

Question, can I pass the callback url in the init when I try to Auth? The app I'm building is used in a CRM application that will get installed on many different websites. I can not setup the application in FaceBook for all of these. With the Twitter api I can just set 开发者_C百科the call back to any url and then pass the callback url when trying to Auth.

In facebook apps you always have to set the url since only calls from that domain are valid. There is no way to make it work to multiple domains as far as I know.