Android / Google
Android: In order to add this calendar to your device, you need to add it to your Google Calendar using a laptop or desktop (annoying, I know) as outlined below.
Google: Click on the "+" next to "other calendars" on the bottom-left hand side of the Google Calendar screen and then "from URL". Copy and paste in the following:
https://football.bkn.dev/euro/2024/ics/?flags
You may then need to set the calendar to synchronise within the Calendar app settings on your device.
You can also get the calendar in a version without flags if you dislike emoji:
https://football.bkn.dev/euro/2024/ics/