The traffic police called and said I parked illegally, but didn't give me a ticket.

There are records on the internet. See whether the document type is 600 1 or 10 1, and 100 1 is a field bill. You must have a voucher number to pay in the bank. If there is no voucher number, you must bring your driver's license and driving license to the illegal traffic police department to re-enter the on-site ticket and pay the fine at the bank.