To find the iCal link and make a small setting in Google Calendar:

1. Go to Settings in your Google Calendar (click the gear icon in the top right corner)
2. Press Settings
3. Look on the left side under “My Calendar Settings”. Click on the name you gave your calendar.
4. On the left side, you will find the link “Access permissions for appointments”. Please check the box next to “Share publicly”.
5. Scroll down on the left side until you find the link “Integrate calendar”.
6. There you will see several links. The two at the bottom are for the iCal link. Please copy only the link “Private address in iCal format”. This link ends with (.ics).
7. Add this iCal link in this iCal field below this description.