In https://wp-events-plugin.com/documentation/event-ical-feeds/
All Future Events
You have one main ical feed, which is the equivalent to your RSS feed in ical format.
The calendar feed is always located in the same place, which is yourwpsite.com/events.ics and if you don’t have permalinks enabled use yoursite.com?ical=1
When you visit this link directly, you’ll be prompted to download an ics file, which you can then open in your calendar clients.
But when I type https://belledonne-sport-nature.fr?ical=1
nothing happens.