Father’s Rights

I hope I don’t stir anyone up but I’m looking for an answer and I’m not sure if I’ll get it but I’m from Louisiana and my boyfriend has a daughter from a previous relationship. We’re going through the whole bitter jealousy thing with the mom. She’s still in love with him blah blah blah. She took him for child support a while back. He pays. He’s had a few warrants for speeding tickets. Which he’s taken care of now. We were told. And I can’t remember by who. But we were told that at any time his daughter is not in the care of the mother. That because he’s paying child support. He can legally go pick her up and take her. He didn’t do this for a while because of his warrants and the mom always threatened to call the cops. But he’s got everything taken care of and he’s tired of not being able to see his daughter. SO MY QUESTION IS: has anyone heard of this as a law in their state or in Louisiana. I’ve tried to search and find anything I can on it but I’m not sure how to search it. I want him to be able to provide the proof to her parents when he goes and gets his daughter. Any father’s rights advice or knowledge is greatly appreciated. I hope no one takes this the wrong way. And gets hurt over it. He doesn’t plan on being forceful or ugly. Just showing up saying hey I’m here to get her. Here’s something saying I can legally take her. And that’s it. Again I’m not looking to upset or hurt any single moms because I know not every woman is like that. But she’s holding her from him and without a custody agreement there is nothing saying he gets her for this day and this day and so on. WHICH HE PLANS ON DOING. but she won’t let him see her until he does.