The instructions at step 7 are making too many assumptions. $PGDATA is an undefined variable that isn't created during the initial install process and rsync daemon on standby must be first setup and running. /srv/pgsql/ ins't a default file path created during install on Debian/RedHat-based systems, so some relevancy is lost in the instructions.
The "pg_basebackup" command also won't work as you're not specifying a copy-to destination.
It also seems something is missing on the standby node to match what's in the host pg_hba.conf file.