How would you know where to look online? There is no URL on the images you uploaded. Is there definitely no more text underneath the signature?
You have to be handed IN WRITING information about how to appeal and how to pay.
If that didn't happen, then you can appeal on the grounds that it wasn't issued in accordance with the regulations.
Unfortunately the regulations are difficult to read at the moment because they were amended.
See
https://www.legislation.gov.uk/uksi/2018/366/regulation/5 but you have to read information in the pink box and apply the amendments.
Look at 5(2) - (g), (h), (i) and (j)
If this information was missing, then you can appeal under 16(3)(a). There were a couple of recent threads with examples of how to write appeals.
Signage also often doesn't comply at the moment and that might offer another ground if York doesn't have correct signs or they aren't in the right places.