Dear @Uzma,
Thank you for reaching out to the Wefugee Community!
Unfortunately, I am not aware of any law which refers to a residence permit based on a non-married relationship. But I also have to add that I am not a lawyer. This does not mean, that there can not be other requirements you might fulfill or meet in future, which could lead to an opportunity to apply for a residence permit. Maybe you can discuss your case with a legal counsellor. Let us know if you need some support in finding one. However, do not hesitate to get back to us with any further questions!
All the best,
Meike