Anyone knows how to integrate Authorize.Net with Prestashop?

I recently started working on Prestashop. Today i installed the Authorize.Net module and i am unable to find the options to add Login ID and Key on configuration page. Below is the url(dont have enough reputation to add image here) of what i can see on configuration page.

http://postimg.org/image/4odwy52u7/

I already have account on Authorize.Net. Kindly guide me whats going wrong and where i can put the Login ID and Key to activate Authorize.Net on my website.

Any help would be greatly appreciated.