Should I mail in my return if my child’s father has efiled her for 2020? She lived with me all year, he has legal custody but $0 recieved for CS. I have pyshical custody

Our court papers say he had the right to claim her, but under our own terms we have changed our custody agreement and she lives with me. I have made it clear I do not want CS payments from him, I just want my daughter to live with me and I will support her financially, but he claimed her without my knowledge. So now I’m out the CS I should receive and the tax money I expected to receive. How can I change this? He claimed her illegally in my opinion! HELP!