Multiple ct600 filed for property business

Hi
I have four years ct600's needing filed. I have always filed the accounts for the company but i did not realise a seperate filing was required for corporation tax (company in loss). One needs done by April 1st 2019! i have paid a fine every year for not submitting a ct600 return with much confusion as i thought by filing my accounts i had done all that was required. so, here we are! i now need to file the returns. The company accounts are all filed online so you can access them. This is a UK company which holds four properties that it refurbed and built for sale but due to the market crash has held them. There are substantial loans in place and a little rental income.