my german isnt super… aber…

by looking at your soundcard… it appears to have 2 stereo line-ins…
so look in manual for midi-usb… and how that works… and until that overbridge is out…
just connect your rythm to stereo-input 1 (probably input 1 and 2 combined)
and your keys to stereoinput 2 (probably input 3 and 4 combined)

how this technically works in your daw: beats me… to many difrent daws…
unless you work with renoise… i wouldnt be able to tell you… so again
manual time