Alder Lake MiniPC - sound via HDMI does not work

Hi,

after some setup troubles (basically, silicon bug in processor, see
thread on freebsd-current mailing list with subject 'UFS bad inode,
mangled entry on Alder Lake-N(100)' jan 27, 2025) I am working with new
MiniPC, SZBOX S12 - Alder Lake N100 CPU, 16 GB RAM, small and
minimalist, still powerfull enough for my needs.

I see no sound output via HDMI possibility, judging from

# cat /dev/sndstat 
Installed devices:
pcm0: <CSCTEK USB Audio and HID> (play/rec) default
No devices installed from userspace.
#

On other boxes with HDMI sound output working, there is an additonal
line in this output

pcm1: <Intel Kaby Lake (HDMI/DP 8ch)> (play)

(or similar), so I understand there is no sound output via HDMI with
present setup. The gpu-firmware-intel-kmod-alderlake-20230625.1402501
firmware package is installed and graphic works quite well in dual
monitor setup, at present with one FullHD and one UHD monitor connected
via HDMI.

Is it possible to send sound output via HDMI with this hardware? Is
there anything I can do for this goal to achieve? Anybody with some
hint?

Regards,
Milan