How to create PostgreSQL database?

I’ve tried to manually create the PostgreSQL database:

postgres=# create role zammad with login password '<the password from database.yml>';

postgres=# create database zammad with owner zammad;

and verified that the zammad operating system user can connect:

ammad@zammad-test:~$ id
uid=999(zammad) gid=996(zammad) gruppi=996(zammad)
zammad@zammad-test:~$ psql -c 'select current_date; ' zammad
 current_date 
--------------
 2024-06-24
(1 riga)

With the database in place, things go a little better but the installation still complains:

# apt install zammad
...
== 20240612071836 CleanupObsoleteTranslations: migrating ======================
== 20240612071836 CleanupObsoleteTranslations: migrated (0.0004s) =============

# Updating translations...
/opt/zammad/vendor/bundle/ruby/3.2.0/gems/activerecord-7.0.8.4/lib/active_record/connection_adapters/postgresql_adapter.rb:768:in `exec_params': PG::ForeignKeyViolation: ERROR:  insert or update on table "translations" violates foreign key constraint "fk_rails_d6e6d9635d" (ActiveRecord::InvalidForeignKey)
DETAIL:  Key (created_by_id)=(1) is not present in table "users".

Just for the record:

# apt search zammad
Ordinamento... Fatto
Ricerca sul testo... Fatto
zammad/sconosciuto,now 6.3.1-1719208095.8ca3e48a.bookworm amd64 [installato]
  Zammad is a web based open source helpdesk/customer support system