calendar – How to subscribe to the .ics calendar of the Internet with Outlook on Mac

I have MS Office 356 for Mac, Outlook 16.22.1. The email part works well. I'm now trying to fit in calendars, but I can not understand it.

Using the usual mechanism of inviting a Windows Outlook person who sends the Mac user the Webcals link, and then trying to open it in Outlook on Mac, the message "None application does not allow to open the URL webcals: // mydom.org/calendres/moncalendrier.ics ".

In the "Calendar" tab of the calendar, "Open Shared Calendar" is grayed out.

So, how do you do this on Mac (High Sierra 10.13.6)?