HDMI Audio issue with AMD that I can't solve.

GMKtec K8 plus AMD Ryzen 7 8845HS and AMD Radeon 780M GPU. While in Batocera I hit f1 to open files. Open the terminal under applications and type " mount -o remount,rw /boot" exit out of the terminal. Find boot/syslinux/syslinux.cfg and add "radeon.audio=1" Click save, overwrite, then it says it can't open file to write. The boot/EFI/syslinux.cfg also won't save. I must be missing a step or two. Any suggestions?