Twitter integration with rails 3 app

I want to login using twiter app for that i used gem 'omniauth-twitter' now please tell me whats app url in twitter when i want to use localhost:3000 i gave http://0.0.0.0:3000 as url

and in call back url my index page
like

localhost:3000/index
my app not able to redirect to twiiter page on click on this link
http://localhost:3000/auth/twitter

please some body help me .....

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