When you click submit, you will see a confirmation page with a button to click to checkout with PayPal. You DO NOT need to have a PayPal account to pay online. Click the "Checkout with PayPal" button on the confirmation page.
If you have a PayPal account: Log in and pay as you always do. From within your PayPal account, you can choose from whatever payment source you have set up (PayPal account, credit card, checking account, etc.).
If you do not have a PayPal account: All you need to do is click the link that says "Pay with a debit or credit card, or PayPal Credit" and a credit card payment form will open up.