Welcome back to the Wefugees Community and thank you for your question.
As I read here (Refugee Council Lower Saxony), people holding a residence permit according to section 19d of the German Residence Act need to hold a respective residence permit for minimum 5 years before they can apply for a permanent residence (Niederlassungserlaubnis). Please see a list of the additional requirements on this website, for instance.
Would you agree dear @mbeon-fardeen?
All the best,