NTA It’s actually a basic human right to know your biological parent and there has been a lot of studies about it being emotionally harmful not to know them. While I don’t think you should have full custody you should be able to spend meaningful time with her a few times a month at least and form some kind of relationship.

Now is the time to do it and honestly - if you do nothing she won’t approach you, she’s a child who doesn’t know what she wants. She’ll just grow up and wonder why you didn’t want her and you didn’t fight for her.

There’s a real attitude that men are hard done by in family law - in my experience men just give up almost immediately because they’ve been socialised to think they don’t matter. You do matter. And even though the little girl doesn’t know it now , she will regret it if you aren’t in her life.