What sound card/s do you have on that PC?
What do you mean by audio not working. Mic's, Speakers, Headphone or all of them?
Have you checked ZorinOS Help re Audio here: Set Up Sound - Zorin Help
Otherwise.
Open alsamixer in terminal.
hit [F5] to display "All" sound channels.
Post a screenshot here.
Also can you amend your forum profle to indicate you have Core edition of ZorinOS. Thanks.
The sound is now working. I installed PulseAudio but did not know you has to reboot to get it to work. So when I did this I could get sound.
I dont understand why Zorin does not by default does not suggest something to be able to allow audio to work.
The sound is on board my Gigabyte X570 Mobo.
Also when I went to settings and then looked for sound it does not appear at all.
Anyway it is working now, so my next challenge is to be able to get Zorin to duplicate my display to the other screen connected.