You can use the "Payment Center" link on your Store Manager to apply or set up online processing, as well as to select which credit cards or payment methods you wish to offer in checkout.
The Payment Center, as well as the Payment Wizard which merchants use before opening for business, allows you to apply for a merchant account from PayPal Payments Pro or Bank of America Merchant Services, set up an existing merchant account, or set up PayPal.
Upon signing up for or setting up a merchant account, your store will be enabled to display all card types available to your merchant account. To add new card types, contact your merchant account provider. You can change the payment options displayed by clicking the Add/Edit Payment Options.
If you are set up for online processing, make sure to select the payment methods that you are set up to process online with your merchant account provider. If you aren't set up for online processing, you can select the payment methods you are willing to accept.