It was confirmed that the connection test was successful.
I have also confirmed that I can execute queries.
Thank you for your support.
If necessary, I will report on github that the event has been resolved.

I think WORKER TIMEOUT is a gunicorn error.
Add the --timeout parameter in the gunicorn settings and
Avoided the timeout by reloading the supervisor inside the container.
I don't think it is recommended to change the settings in the container, so I think it is necessary to deal with it as a separate matter.
/etc/supervisor/conf.d/redash.conf
[program:web]
directory=/app/code/redash
command=/app/code/redash/bin/run gunicorn -b 0.0.0.0:5000 --name redash -w 4 --max-requests 1000 --timeout 300 redash.wsgi:app
process_name=server
user=cloudron
numprocs=1
autostart=true
autorestart=true
stdout_logfile=/dev/stdout
stdout_logfile_maxbytes=0
stderr_logfile=/dev/stderr
stderr_logfile_maxbytes=0
run sudo supervisorctl reload command.
Test connection is failing with Athena integration due to the following events.
https://github.com/getredash/redash/issues/5561
Is there anyone who is already using it?
Is it possible to use an older version of Redash with Cloudron?