[MM3-users] Still unable to get mailman3 working on Ubuntu 20.04 LTS

Michael Heseltine writes:

and type in the password listed in settings_local.py,

All of the settings*.py files are for Django, that is, for Postorius and HyperKitty.

Configuration of Mailman 3 core is mostly done in .cfg files, typically in /etc/mailman but I don't know about the instructions you're following. From docs/database.rst:

You would then need to set both the `class` and `url` variables in
`mailman.cfg` like so::

[database]
class: mailman.database.postgresql.PostgreSQLDatabase
url: postgres://myuser:mypassword@mypghost/mailman

The "class" line is verbatim. In the "url" line the words beginning with "my" are dummies that you need to replace with the appropriate values.

Howto_Install_Mailman3_On_Debian10 provides a template for mailman.cfg which you may want to copy and customize at least the passwords)

Steve