Germany has embassies or consulates in almost every country in the world. There is often only one embassy per country - this is then responsible for all people from that country. In large countries in particular, however, there are often several consulates, each of which is responsible for one region. The exact distribution of responsibilities is then explained on the embassy's website. You can find a map of all German missions abroad here.
The abbreviation BVA stands for Federal Office of Administration. The Federal Office of Administration deals centrally with administrative tasks that are the responsibility of the federal government. As the individual federal states are generally responsible for naturalizations, the Federal Office of Administration only processes naturalization applications that are submitted from abroad. The Federal Office of Administration is also responsible for applications for the retention or release of German citizenship, as well as applications for the determination of the (non-)existence of German citizenship or the acquisition of a declaration.
