After you have create your Subscription Calendar link in Jezzam, you need to copy the link and then subscribe to the calendar using the link.  


See below for more information on how to subscribe to a calendar in the major calendar apps:


Google Calendar:

https://support.google.com/calendar/answer/37100 ("Add using a link" section)


Outlook: 

https://support.office.com/en-gb/article/import-or-subscribe-to-a-calendar-in-outlook-on-the-web-503ffaf6-7b86-44fe-8dd6-8099d95f38df


Apple Calendar:

https://support.apple.com/en-gb/guide/calendar/icl1022/mac