Edit: I just found this. It's only possible for PC gamers
19. Is it possible to add FIFA Points to my account on the Web?
You can add FIFA Points to your PC account directly within the web app. By clicking on the ‘Get More’ option in the top right corner of the app.
On console you can only buy FIFA Points through the FUT Store in FIFA 13 on your Xbox 360® or Playstation®3. Once purchased you can use FIFA Points to buy packs in the FUT Pack Store on Xbox 360®, Playstation®3, and in the web app.