All purchases made in the in-game shop are processed by Google Play. Available payment methods may vary depending on your country, which means that some methods may not be available for you. The most common methods are the following:

– Credit or debit cards
– Direct carrier billing
– Prepaid or gift cards
– Paypal

For more information on how to set up and use these payment methods or what payment methods are available for you, please visit Google Play Support.