CCJ warning letter

Hi all. In 2023 I received a letter from parking eye stating I parked in a private car in 2021 when that was not the case. The 2nd time i received a letter, I remember sending something but cant remember what I sent but since then I ignored the letters they sent. Today a letter from county court judgment saying if i dont pay i will get a CCJ.

What can be done?

I dont live there anymore although my family do

Please help as I am really stressed now