Adoption

This IS NOT about me, this is about my brother in law and I'm just curious because I have no clue how it works.

So his ex who had a child with him, and she now want her husband of 6 months to adopt the child. She says the father has not tried to see the child in 3 years or whatever (I'm not exactly sure of the whole story) but she says that because she's been married for 6 months and he has not tried to see her in 3 years that the court will be in her favor.

Well my main question is, regardless the situation, doesn't the real father have to agree to sign the baby over?

Thank you in advance 😊