iOS (Apple Calendar App)
On your iPhone or iPad, open your device settings. Scroll and tap Passwords & Accounts. Tap Add account Other. Tap Add Subscribed Calendar Copy & paste this public ICS feed: https://calendar.google.com/calendar/ical/apbf.dog_601sep9ijbd8ub92j8uu30n9ns%40group.calendar.google.com/public/basic.ics