If you have Netflix in DE you can also watch foreign series and also in their language or they are only available in that country
Unless you have a VPN, only those that are approved for Germany.
The country code only allows the films that are broadcast in the respective reception area.
Netflix asks which country you're looking from. So when I travel to Asia, I can't watch certain series, for example, because they are not available in this country. But I can look at something else that is not available here in Europe.
You can change the whole thing via VPN. You can do this yourself or you can let external services do it for you.
Since changing the VPN is not a concern of Netflix, you have to read for yourself how to do it
Of course you can also watch foreign and not only German series and these in their language (if you want with German subtitles). I recently watched the Norwegian Netflix series Ragnarok, in Norwegian with a German subtitle ✌️