Welcome to the Wefugees Community and thank you for reaching out to us.
I am afraid that I can not give you a general answer on your question. As far as I know, for proving the German language level B1, the authorities usually ask for 4 years enrollment in a German school, (successfully) finishing the 10th grade, or complete the integration course, for instance.
Am I right on this, dear @mbeon-fardeen? In any case, I would recommend you to contact the immigration office (Ausländerbehörde) to get an individual and reliable assessment of your situation or to register for a B1-exam directly.
Also don’t hesitate to get back to us with any further questions.
All the best,