This feature is only available in Akeeba Backup Professional.
Requires the Enable Legacy Front-end Backup API (remote CRON jobs) option to be enabled in the component's Options, Frontend tab.
In order to schedule a backup failure check, you will have to use the following command line to your host's CRON interface:
/usr/local/bin/php/home/USER/webroot/cli/joomla.php akeeba:backup:alternate_check:upload
where /usr/local/bin/php is the path to your PHP CLI executable and /home/USER/webroot is the absolute path to your web site's root. You can get this information from your host.
The same considerations and scheduling information as the alternative backup CRON script apply.