Yes you can add credits to your account using your Credit / Debit card.
Step 1 : You would need to go to "Settings -> Billing" and click on "Add Funds".
Step 2 : Select Payment method as PayPal and enter the amount of credits you require and press Add Funds button.
Step 3 : You will be taken to the payment page, over there you can select "Pay with my Debit or Credit Card" Option from the right side of the page.
