The supervisor installer installs its own copy of PostgreSQL, running on a non-standard port 50055, and creates and uses the user "qube" to access the database named "pfx". The "qube" user is the owner of the "pfx" database.
(An OS user "pfx" is also created by the installer, who owns the data files and runs the server processes.)
The password to the "qube" user is left blank by default, but you can set it if you desire. Refer to the PostgreSQL reference on pg_hba.conf file and ALTER ROLE:
Once PostgreSQL is configured to use password authentication, you need to configure the Supervisor by editing its qb.conf to set the password, with the following parameter: