= use psql to issue commands to postgres instance: =
== make password for admin user ==
psql> ALTER USER postgres WITH ENCRYPTED PASSWORD 'example';
psql> \q
open /etc/postgresql/NUMBER/main/pg_hba.conf
replace 'trust' with 'scram-sha-256'. save and exit.
$ service postgresql restart
$ psql --username postgres --dbname postgres # provide password
Execute commands from postgres_script.txt