1. Open the App Store on your iPhone
2. Click on the sign-in icon or your picture on the top-right corner of the screen
3. Tap on Redeem Gift Card or Code
4. Copy the iTunes gift card code from Poll Pay app, Google Opinion Rewards, or email and paste it by clicking on, “You can also enter your code manually”
5. Click on Done and the gift card amount will be added to your Apple ID balance
6. Now, open Free Fire and tap on the diamond icon
7. Select the diamonds bundle and proceed to pay
8. Confirm payment using Face ID, Touch ID, or manually entering your password to get Free Fire diamonds