On the Facebook app dashboard :
- in the "App Domains" field put : asknoypi.com
- in the "Website with Facebook login" section, in the "Site URL" field put (for example) :
http://www.asknoypi.com/ask
This value must be equal to the value in the "Preferred site URL" field on q2a (admin panel settings). In this case the "Preferred site URL" of your site should be also : http://www.asknoypi.com/ask
- you do not need to fill the other sections ("App on Facebook" and "Mobile Web")