In order to use Calendar Sync for Jira with the desktop version of Microsoft Outlook, follow the steps below.
In Jira, click your profile icon in the top right-hand corner of the screen. A menu will appear. Click My calendars.
The page shows all the feeds and calendars available to you.
Copy calendar URL to clipboard using the Copy to clipboard button, or directly from the text field.
In Microsoft Outlook Calendar, expand the dropdown for Open Calendar and select From Internet....
Paste the address from clipboard and click OK. An example URL is shown here; your URL will be much different.
Confirm the subscription.
After a short while the calendar will appear under Other Calendars and in the main window.
Outlook synchronizes the calendars whenever the Send / Receive action is performed, whether it's invoked manually or with the automatic polling interval.