Error about: ALSA lib

[Singularity0104]

Sorry to bother you. When I tried to execute the main.py on a headless machine, there came some errors about:

ALSA lib confmisc.c:855:(parse_card) cannot find card '0'
ALSA lib conf.c:5204:(_snd_config_evaluate) function snd_func_card_driver returned error: No such device
ALSA lib confmisc.c:422:(snd_func_concat) error evaluating strings
ALSA lib conf.c:5204:(_snd_config_evaluate) function snd_func_concat returned error: No such device
ALSA lib confmisc.c:1342:(snd_func_refer) error evaluating name
ALSA lib conf.c:5204:(_snd_config_evaluate) function snd_func_refer returned error: No such device
ALSA lib conf.c:5727:(snd_config_expand) Evaluate error: No such device
ALSA lib pcm.c:2721:(snd_pcm_open_noupdate) Unknown PCM default
ALSA lib confmisc.c:855:(parse_card) cannot find card '0'
ALSA lib conf.c:5204:(_snd_config_evaluate) function snd_func_card_driver returned error: No such device
ALSA lib confmisc.c:422:(snd_func_concat) error evaluating strings
ALSA lib conf.c:5204:(_snd_config_evaluate) function snd_func_concat returned error: No such device
ALSA lib confmisc.c:1342:(snd_func_refer) error evaluating name
ALSA lib conf.c:5204:(_snd_config_evaluate) function snd_func_refer returned error: No such device
ALSA lib conf.c:5727:(snd_config_expand) Evaluate error: No such device
ALSA lib pcm.c:2721:(snd_pcm_open_noupdate) Unknown PCM default

I am wondering what causes these problems and how to fix it. Thank you!