I’m running into problems I am able to get sound from the tv but not the stereo any ideas what may be going on..

Hey I’m trying to setup a Xbox one s to my older brothers 90s kenwood home stereo. I’m running into problems I am able to get sound from the tv but not the stereo any ideas what may be going on... tv is a Panasonic 2014 smart tv to a XB1s to and 90s kenwood home stereo