Filing taxes help!

Anyone have any experience or knowledge on both parents filing for child even though the dad doesn’t have custody, permission, and kid hasn’t lived with them all year? He’s trying to file but I told him not to since our child doesn’t live with him, I haven’t given him permission, and our child doesn’t live with him. Our child doesn’t have his last name and he isn’t on our childs birth certificate. He just wants and cares about the money which is pathetic to me. He thinks he is entitled to file and entitled to the money which is bs. I’ve taken care of our child far more than he has. He’s gotten our child clothes, shoes, and toys a handful of times. I’ve spent thousands on my kid so for him to think he deserves the money while I’m providing and taking care or our kid while he does the bare minimum and barely does anything, he has to be insane. I haven’t worked all year besides for/with him a few times last year so I don’t really have anything to put down for income when filing. Would I get any money back if I file with no income put? Should I let my mom file us since I’ve lived with her most the year of 2022?