Welcome to the Wefugees Community and thank you for reaching out to us.
I am afraid that your situation is different to the one dear @someoneingermany is referring to. In the earlier discussed case, the mother of the child was not married. I am not an expert in this legal field, but as far as I know, the husband of the mother will always be the legal father - even if he is not in the biological sense. For the biological father, it is very complicated and only possible under very specific conditions (like the mother being in the divorce procedure already etc.) to be formally recognized as father. You would need to go through a so-called “Vaterschaftsanfechtung” in court.
I am sorry that I can not give you more hopeful information. However, I will also link dear @mbeon-Ruth and @mbeon-Rukundo here. Do you agree with me and/or can you give some more details on this?
In any case, please don’t hesitate to get back to us with any further questions.
All the best, Meike