At startup, no signal from input source - MacOS

[massimogullotto]

The Web interface shows in the Input info: "avfoundation -video_size 1280x720 -framerate 30: '0:0'
No signal"

MacBook Pro (13-inch, 2017) - MacOS Catalina 10.15.7

tail -f /var/log/apache2/broadcaster-error_log
[Sat Feb 27 22:09:27.574402 2021] [wsgi:error] [pid 94138] [client 127.0.0.1:54142] All Ok, encoder started successfully, referer: http://127.0.0.1:8888/
[Sat Feb 27 22:10:14.939183 2021] [wsgi:error] [pid 94230] [client 127.0.0.1:54323] Audio Card NOT found, referer: http://127.0.0.1:8888/
[Sat Feb 27 22:10:14.963216 2021] [wsgi:error] [pid 94230] [client 127.0.0.1:54323] input_src_id None, referer: http://127.0.0.1:8888/
[Sat Feb 27 22:10:14.964178 2021] [wsgi:error] [pid 94230] [client 127.0.0.1:54323] INSERT INTO CapInputNames  ( InputInterface, InputId, InputUrl )  VALUES( "avfoundation -video_size 1280x720 -framerate 30", "0", " '0:0'" ) , referer: http://127.0.0.1:8888/
[Sat Feb 27 22:17:57.133929 2021] [wsgi:error] [pid 94231] [client 127.0.0.1:56292] Audio Card NOT found, referer: http://127.0.0.1:8888/
[Sat Feb 27 22:17:57.156984 2021] [wsgi:error] [pid 94231] [client 127.0.0.1:56292] input_src_id None, referer: http://127.0.0.1:8888/
[Sat Feb 27 22:17:57.157980 2021] [wsgi:error] [pid 94231] [client 127.0.0.1:56292] INSERT INTO CapInputNames  ( InputInterface, InputId, InputUrl )  VALUES( "avfoundation -video_size 1280x720 -framerate 30", "0", " '0:0'" ) , referer: http://127.0.0.1:8888/
[Sat Feb 27 22:27:18.553508 2021] [wsgi:error] [pid 1940] [client 127.0.0.1:49508] Audio Card NOT found, referer: http://127.0.0.1:8888/
[Sat Feb 27 22:27:18.578153 2021] [wsgi:error] [pid 1940] [client 127.0.0.1:49508] input_src_id None, referer: http://127.0.0.1:8888/
[Sat Feb 27 22:27:18.579314 2021] [wsgi:error] [pid 1940] [client 127.0.0.1:49508] INSERT INTO CapInputNames  ( InputInterface, InputId, InputUrl )  VALUES( "avfoundation -video_size 1280x720 -framerate 30", "0", " '0:0'" ) , referer: http://127.0.0.1:8888/