Cron doesn't work in Hikasop starter

-- HikaShop version -- : 4.0.3
-- Joomla version -- : 3.9.4
-- PHP version -- : 7.1.26
-- Browser(s) name and version -- : Firefox Quantum 66.0.1 (64 bits)
-- Error-message(debug-mod must be tuned on) -- : Call to undefined method stdClass::cron()
/home/zzzzzzzzzzzzzzzzzzzzzzzzzzzzz/plugins/system/hikashoppayment/hikashoppayment.php:121
Call stack
# Function Location
1 () JROOT/plugins/system/hikashoppayment/hikashoppayment.php:121
2 plgSystemHikashoppayment->processCronNotification() JROOT/plugins/system/hikashoppayment/hikashoppayment.php:43
3 plgSystemHikashoppayment->onAfterInitialise() JROOT/libraries/joomla/event/event.php:70
4 JEvent->update() JROOT/libraries/joomla/event/dispatcher.php:160
5 JEventDispatcher->trigger() JROOT/libraries/src/Application/BaseApplication.php:108
6 Joomla\CMS\Application\BaseApplication->triggerEvent() JROOT/libraries/src/Application/CMSApplication.php:626
7 Joomla\CMS\Application\CMSApplication->initialiseApp() JROOT/libraries/src/Application/SiteApplication.php:686
8 Joomla\CMS\Application\SiteApplication->initialiseApp() JROOT/libraries/src/Application/SiteApplication.php:212
9 Joomla\CMS\Application\SiteApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:196
10 Joomla\CMS\Application\CMSApplication->execute() JROOT/index.php:49

Hi.
After discussion about Subscription, I try the cron link and it doesn't work :

Call to undefined method stdClass::cron()
/home/zzzzzzzzzzzzzzzzzzzzzzzzzzzzz/plugins/system/hikashoppayment/hikashoppayment.php:121
Call stack
# Function Location
1 () JROOT/plugins/system/hikashoppayment/hikashoppayment.php:121
2 plgSystemHikashoppayment->processCronNotification() JROOT/plugins/system/hikashoppayment/hikashoppayment.php:43
3 plgSystemHikashoppayment->onAfterInitialise() JROOT/libraries/joomla/event/event.php:70
4 JEvent->update() JROOT/libraries/joomla/event/dispatcher.php:160
5 JEventDispatcher->trigger() JROOT/libraries/src/Application/BaseApplication.php:108
6 Joomla\CMS\Application\BaseApplication->triggerEvent() JROOT/libraries/src/Application/CMSApplication.php:626
7 Joomla\CMS\Application\CMSApplication->initialiseApp() JROOT/libraries/src/Application/SiteApplication.php:686
8 Joomla\CMS\Application\SiteApplication->initialiseApp() JROOT/libraries/src/Application/SiteApplication.php:212
9 Joomla\CMS\Application\SiteApplication->doExecute() JROOT/libraries/src/Application/CMSApplication.php:196
10 Joomla\CMS\Application\CMSApplication->execute() JROOT/index.php:49

Hi.
Thank you for discussing this together and proposing this alternative.
I can indeed see with the client the advantages of moving to a commercial version of HikaShop.
Thank you again!

Hello.
After a long silence, my client comes back and asks me to activate his site.
The website is up to date with Hikashop Starter 4.3.0 and Hikaserial Subscription 3.0.1.

However, calling the cron task (/index.php?option=com_hikashop&ctrl=cron) results in :
> Alerte
> Page not found: cron

What to do? Is the cron task definitely not available for the starter version of Hikashop?

Thank you in advance for your answer.
Best regards.
AlainR