Cubase ai 11 when I try to record keyboard and voice it doesn’t work

I downloaded everything right but when I try to record keyboard and voice it doesn’t work.
Is this because I received for free when I bought a cubase version that it works only with this kind of keyboard (I try with another Yamaha) or something else ?
For other things it works.
Nb : I use Scarlett solo 3rd generation

Thank you

No it should work. You need to explain exactly how you are doing it. Are you recording midi and audio or trying to record both audio. If you have chosen the solo as your audio device then Cubase can only use one audio interface so it won’t record audio from your keyboard usb and the Scarlett interface at the same time. Options are plug mono out into Scarlett instrument in or just record midi and let that play back the keyboard. You would still need to put into the Scarlett though to monitor or get a small mixer.