Where is the seahub_settings.py in a docker install?

I have a docker install, and I am trying to add e-mail notification functionality. I have found the document to help me do that, (haven’t found documentation that says it can be set as an environment variable) but can’t find the document to tell me where the file is I need to edit.
Lil help?

This file is located in your shared folder located at:
/shared/seafile/conf
However for future readers please note that the document located at:
(can’t post the link, its in the manual)
at the time of this writing contains an INCORRECT SYNTAX and will cause seafile not to start. Both EMAIL_HOST_USER should have single quotes around them as follows:
DEFAULT_FROM_EMAIL = EMAIL_HOST_USER
SERVER_EMAIL = EMAIL_HOST_USER
should be changed to
DEFAULT_FROM_EMAIL = ‘EMAIL_HOST_USER’
SERVER_EMAIL = ‘EMAIL_HOST_USER’