Hubstaff Activity Sync Automation
Synchronization between the two systems is performed daily during the standard WHMCS Cron operation. Reference Automation for more details and options.
To run the sync more often you can setup a cron to call the Hubstaff Addon cron job directly.
Create a cron using PHP
php -q /you_whmcs_path/modules/addons/hubstaff/cron.php
Create the following Cron Job using GET