I'm developing an Android application in which user have to buy coins to use features of app. I want to know which is the best way to achieve my goal. I have read about Google Pay and Google In-App billing, but i am unable to understand which payment type should be implemented in my case. I have calling feature in my app, user have to buy coins to use this feature, a certain amount of coins will be deducted per minute when user calls someone, so user have to buy coins first.
I want to know if Google Pay is better or Google In-App billing is better for my application. Or if there is any other way to do this, i would really appreciate your opinion. Thank you in advance.