If you're logged in to your Google account, click on the +GoogleCalendar button located towards the bottom right corner of the calendar to subscribe.
If you're subscribing by link, follow the "Add using a link" steps provided on this page. The ICAL link for the Allies calendar is:
https://calendar.google.com/calendar/ical/mail.fresnostate.edu_65u0v38cv227b44u4fin7bp7d8%40group.calendar.google.com/public/basic.ics