Hello,
The on-line documentation doesn't cover the old version. You'll have to download the PDF version of the documentation from Akeeba Backup 3.4.3's download page and look up the Automating Your Backups section.
The location of the CRON script in older versions of Akeeba Backup is your site's administrator/components/com_akeeba/backup.php file. You'll probably have to ask your host to help you determining the absolute path to that file. Also note that the options use a single dash in that old version.
Nicholas K. Dionysopoulos
Lead Developer and Director
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