Seems to be a common problem to have sound issues on Galaxy Books.
This thread has solution for Fedora and also Debian. The Debian solution should be usable by you:
https://forums.fedoraforum.org/showthread.php?331130-Fixing-ALC298-audio-(no-sound-from-speakers)
Here's an arch and manjaro solution to help you figure it out if the above doesn't solve your troubles. :
https://bbs.archlinux.org/viewtopic.php?id=269385
https://forum.manjaro.org/t/howto-set-up-the-audio-card-in-samsung-galaxy-book/37090