Answers for "postgres create user with pgadmin"

psql create user

# https://www.postgresql.org/docs/8.0/sql-createuser.html
CREATE USER <username> WITH PASSWORD '<password>' VALID UNTIL '<date here>';

postgres create admin user with password

sudo -u postgres createuser -s -i -d -r -l -w <<username>>
sudo -u postgres psql -c "ALTER ROLE <<username>> WITH PASSWORD '<<password>>';"