There are two places to add and/or update your payment types.
1. The first is during checkout when you're placing an order:
Choose a payment type, and then fill in your billing details then click the red "Continue" button to proceed through the checkout process.
If you’ve already filled in your payment details in the past and the checkout page transfers you straight to the last step of the process (Review order), you can change the settings and your preferred payment method here by clicking the Change button under Payment information.
2. The second way to manage your payment information is in your account settings. To get there, login to your account and click on your profile image at the top right corner of the screen. When the menu appears, click "Settings." Then click "Shipping & Billing" from the menu at the top of the page. Here, you can add, update, and remove shipping and billing information from your account.