Sticky situation..

Hello all, I am desperately in need of some advice. I had a baby in 2022, the father of the child doesn't know that it's his. When he found out I was pregnant in 2021, he said he hoped it wasn't his, he wasn't ready for another child etc (it was a one night stand, although we did have a relationship many years ago previously). So to save the aggro I lied and said it was someone elses.. when infact there was never anyone else, and he was the only one I'd slept with for years, so 100% I knew he was the father. I have wanted to tell him for ages now, and even invited him to do a paternity test last year which he said he was down for, but it never materialised. I really want to tell him that I know my son is his, there was never another man, I lied because I was scared etc... how should I do this? I want him to have the chance to be involved, but if he doesn't want to be, that is also fine. How do I go about this? All advice is welcome, and please no bashing!