Dear @Mashoko,
Welcome back at Wefugees and thank you for your question.
I highly recommend you to apply for the residence pemit according to section 25b before your current permit (104c) expires - especially if the proof of the language skills is the only requirement you still have to meet. Please also emphasize at the immigration office (Ausländerbehörde) that you have an appointment for the certificate already in January 2025.
As far as I understood, the immigration office will issue a "Fiktionsbescheinigung" which will give you a bit time to add the required documents to your application. With the Fiktionsbescheinigung you are probably also allowed to work.
Do you agree with my explanations dear @mbeon-fardenn or @mbeon-Éanna?
All the best,
Meike