How do I file for child abandonment?

So the father of my children has been completely absent since June of 2020. We had a very intense physical altercation back then that granted myself and our (at the time) 3 year old son a restraining order for 365. I was (at the time) pregnant with another son. He held the last baby one time. And has been a ghost dad since. He uses Facebook to “claim” he “wants” to be there but I give him schedules, meet up times, yada yada and he DOES NOT SHOW UP EVER. He won’t sign his rights away, I’ve asked him. I just want every connection my kids have to him to be vanished.