Check the ticket for details of who to contact re making an appeal. I did the same a few weeks ago after receiving a fine because my ticket wasn’t displayed correctly. Turns out the wind had blown it over on the dash (windows slightly down due to dog in the back + very windy day + parked at the front of the multi-storey).
Emailed my appeal along with pic of the ticket, received a response within 24 hr saying they were waiving the fine but let this be a lesson, i.e. make sure the ticket remains in proper view.
Sorted.