Game can be activated on Origin, enables you to play on official EA servers and your game will be kept updated with the latest patches via the Origin platform.
Login to your Origin account or create one here - https://connect.origin.com/create
Click "Origin" in the top left corner of the window.
Click "Redeem Product Code...".
Enter your code and click "Next".
Confirm your code redemption by clicking "Next".
You product activation should be confirmed by the text in green.