google play store - Change Gmail account to make in-app purchase?

What is the procedure to change email account which you want to use to make in-app purchase?

Take a look at the image.

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I am using 2 Gmail accounts and only 1 has a credit card attached. The primary account has a credit card, the secondary does not. But my secondary account is always in the payment dialogue. The secondary account is also not the account used in Play Store app.

I found no way to change this email.