Back on Monday, I had my work visa interview with section 81a advance approval document in the German Embassy. My company is in Berlin, so my employer had got the 81a issue document issued by Landesamt Für Einwanderung.
During the interview, the interviewer had a sample document, and he clearly told me that the document must be issued by the alien authority, and I kept telling him that every state in Germany has a different alien authority, for example, in Frankfurt it's known as Ausländerbehörde Frankfurt
Although I have done my own research, I'd just like to confirm that words like foreign authority, alien authority, immigration authority for Berlin always point to Landesamt Für Einwanderung, or these are different things?
P.S: in the coming days, I will have my interview again in the diplomatic mission.