There are 2 previous posts on here about the same model laptop
Just installed Manjaro and no sound at all
No sound in Manjaro GNOME
The ALSA data from 2nd discussion is showing OP has the correct ALSA modules loaded to detect both HDMI and onboard audio devices recognised
!!Loaded ALSA modules
!!-------------------
snd_hda_intel
snd_soc_skl_hda_dsp
!!Soundcards recognised by ALSA
!!-----------------------------
0 [NVidia ]: HDA-Intel - HDA NVidia
HDA NVidia at 0xa4080000 irq 17
1 [sofhdadsp ]: sof-hda-dsp - sof-hda-dsp
ASUSTeKCOMPUTERINC.-TUFGamingFX505GT_FX505GT-1.0-FX505GT
But your latest alsa-info data is still not showing only HDMI audio device is recognised
https://alsa-project.org/db/?f=1181fc4036f2100f9895f6e20deb8166dce46784
and some of the sof-firmware modules appear to be missing from !!All Loaded Modules
snd_soc_skl
snd_soc_skl_hda_dsp
snd_soc_sst_dsp
snd_soc_sst_ipc
I suggest you install (or reinstall) sof-firmware
pamac install sof-firmware
and check dmesg and alsa-info again if onboard audio is not being detected