Trouble with the recognition of my motherboard audio controller.

[mahesh]

Hello, I just bought a second hand "ASUS ROG Z390-E Gaming" motherboard. It comes with an on-board HD 7.1 CH audio card. But somehow, my Ubuntu doesn't recognize it: instead, it claims the only available "Adio source" is using my Radeon RX-580, which is my graphic card, as sound output, via it's HDMI port. And no sound input is shown as even available. I tried installing my SoundBlaster Audigy RX, but it isn't recognized neither. Any ideas please? Thanks a lot for your time and patience with a newbie!