Can't set up a connection to GMX cloud (one year subscription)

Hi,

the Help page says that most supported Clouds are automatically recognised and displayed by Boxcryptor.

The GMX cloud IS supported, but apparently not recognised.
How do I get Boxcryptor to recognise my Cloud storage?

Or...

The Help page talks about adding the storage manually, if it is not recognised automatically.

How EXACTLY does this work for GMX?

Regards,
Jochen