Sign in with the email that was used to set up AutoPay, and go to the WaterBot dashboard.
Select "Manage AutoPay." Next select your account, click "Submit," then choose "My Payment Method."
A payment method will be displayed with a blue arrow to the right. Click on the blue arrow and then select the payment method you want to be linked to your AutoPay.
Once you have selected a payment method, click the blue "Submit" button, then click "Super, thanks." You have now successfully changed your payment method for automatic payments.