It’s simple. When users will see the following screen somewhere in your application, you are requesting data from Facebook:
Please note that I’m not a lawyer and I don’t have any legal experience. When you want to be certain, please seek advice from someone with legal knowledge.
Once done, you need to copy the URL/link of that page (e.g. http://yourdomain.com/wp4fb/privacy-policy/).
Navigate to the Facebook App section and start editing the application by clicking on “Edit App”. In the left-menu, click on “App Details” (see image on the right).
That’s it! That’s all you need to do 🙂