You must have a credit card on file to create an account. But you can pay your balance with PayPal if your credit card is expired or is no longer accepting charges.
Navigate to the Billing tab of Event Manager at https://login.photopartyupload.com/Billing/Index
Scroll to the bottom, and you should see a PayPal Pay Now button:
Click the button, and pay your balance through PayPal on a secure page.