Gift Cards are managed by the store where you made your purchase. They can’t be redeemed inside the game. Here’s how to use them depending on the provider:
Apple Gift Cards:
Apple manages all payments and balances.
For help redeeming or using a card, visit: Apple Support
Google Play Gift Cards:
Google manages all payments and balances.
Your Google Play account country must match the country where the card was issued.
If you see a message that your card isn’t valid, check this guide: Google Play Help
For more help, contact Google Play Support: Google Play Support
Amazon Gift Cards:
Amazon manages all payments and balances.
For help redeeming or using a card, visit: Amazon Support
Keep in mind that Gift Card balances are always handled by the provider, not in the game.