It's the user's job to create users with the appropriate roles.
TUGDJU23SQQKDEIUKEMAYVJVD24SSZ42OFZSKQPWDXOVLN7AMHAQC
${config.services.postgresql.package}/bin/psql hydra << EOF
BEGIN;
INSERT INTO Users(userName, emailAddress, password) VALUES ('admin', '${cfg.notificationSender}', '$(echo -n $pass | sha1sum | cut -c1-40)');
INSERT INTO UserRoles(userName, role) values('admin', 'admin');
COMMIT;
EOF