I have to keep checking back to see which flavour of Zorin 15 you have. i.e. Lite education with xfce desktop environment. @Aravisian is more familiar with Lite as I have Core (gnome DE).
Do you have Synaptic Package Manager installed. If you do, search for alsa-tools-gui with that and install.
I checked it should be available in Ubuntu-Universe repository. https://ubuntu.pkgs.org/18.04/ubuntu-universe-amd64/alsa-tools-gui_1.1.3-1_amd64.deb.html