How to charge using iPhone, iPad or iPod :
- Sign in to your App Store account.
- Scroll down to the bottom of the page, then select the Redeem icon.
- Choose the second option You can also enter your code manually , then copy the code sent to you and paste it in the required field.
- From the top of the page, choose the word Redeem to replace the code.
- Congratulations! You can now enjoy purchasing paid content now that your account is charged.