Not sure how to answer this needing help/advice

Laura • Mom of 2 with one on the way...❤️

My unborn sons father is asking me how he can be there for the child when we aren’t together at all. But says he won’t sign the birth certificate and wants to keep it civil and doesn’t want to have nothing in writing. I personally love this man to death and want to be with him, have my child have a father. But cause he’s choosing his path I’m sitting here like ok what do I do.