Add or change your billing information from the Settings page.
To update your billing information, navigate to User Settings > Profile. From there, locate the "Payment Method" field and click on the button to add or change your payment method. Click on "Edit Billing Info" to add or edit your billing information.
Once you have at least one payment method connected to Breadcrumbs, you'll see it listed and you'll be able to edit it or add a new one.