Automatic language selection

I just installed Hikashop. After that, it told me, that there is a language file with my language existent.
But the language file, which showed up looked like an english language file, not like de-DE.
See:

Depending on your server settings and your browser, HikaShop might not be able to download the language file.
In such cases, you can download the file directly on our website:
www.hikashop.com/en/download/languages.html
and upload it to the folder languages/de-DE (the language code will depend on your language).

I have downloaded the server. But where I will upload the file?

It's explained in the documentation link I gave:

For any reason, if your language file could not be automatically installed, you can manually download it below and upload it in the folder language/TAG (you need to replace TAG by the tag of your language) of your website via FTP