Open the Google Play Store app
Tap your profile icon
Tap Payments and subscriptions
Tap Payment methods
Add a credit or debit card, PayPal, carrier billing, or another available payment method
To use Google Play balance, redeem a Google Play gift card or promo code
Open the Google Play app and tap your profile icon
Tap Payments and subscriptions
Tap Redeem code
Enter the code and tap Redeem
Use the added payment method or Google Play balance for purchases in Google Play