Please follow the steps below:
Through the website
Go to myaccount.ea.com.
Click on the “Redeem Product Code” tab.
Type in your product code, then click “Next”.
Through the App
Launch the EA app.
Log in to your EA Account.
Open “My Collection”.
Select “Redeem Code”.
Through the Origin client
Log in with the EA Account where you want to add the game.
Click the Origin menu.
Select “Redeem Product Code”.