How to enable LDAP authentication for schema SSHA384

[Ralph Seichter]

While using LDAP-based authentication, I have come across the message

  auth: Error: [...] Unknown scheme SSHA384

Based on the docs at [1] I use the dovecot.org packages provided for
Ubuntu 20.04 LTS which, as you can see, are not yet documented in the
HTML page, put are available via [2]. Specifically, I used

  apt-get install dovecot-ldap dovecot-sqlite

to install Dovecot. What else is needed beyond the two listed packages
in order to enable support for SSHA384 password hashes in Dovecot? Am I
perhaps missing some required configuration parameter? Your help is
appreciated.

-Ralph

[1] https://doc.dovecot.org/installation_guide/dovecot_community_repositories/ubuntu_packages/
[2] http://repo.dovecot.org/ce-2.3-latest/ubuntu/focal/