Received fine for missing car city sticker, can I pay online?

I recently received the hefty $200 fine for not displaying the city sticker on my car. It's okay, I was stupid and it's fair that I pay.

But when I try to search from my fine online at chicago.gov/parking , as indicated on the fine, the system tells me it can't find the number associated to the fine. Does this mean that I can't pay online? What am I missing here?

EDIT: just to clarify, I never bought the sticker in the first place when I moved to Chicago because I didn't know I had to buy one. Ignorance of law is not an excuse and I fucked up, that is okay, I am not trying to get out of the fine, it hurts but it is what it is.

However, I would like to be able to pay it online if possible.

UPDATE 12/10/2024: the fine has been posted online and I paid it. It just took a long time to be put in the system. Thanks to all that helped me on this.