To schedule your posts, Cron jobs must be configured on your server. In Cpanel, you should click Cron task and fill this command at the command filed.
To get the cron jobs link go to the management page and click on the cronjons item on the menu.
If your hosting doesn't support the Cron jobs, you should consider migrating to another hosting or use Cron jobs from third party services.
Follow the instruction video below to proceed with configuring cron jobs