This is probably because you are using a Google Account's primary calendar from a G-Suite account, and G-Suite settings prohibit sharing the primary calendar.
To resolve this issue, you can either ask your G-Suite administrator to adjust permissions, or you can create a secondary calendar for the selected account that has a "private address in iCal format". Both approaches are explained in this article.
VARIANT 1: Adjust authorization in G-Suite account
- Log in here with your G-Suite account. If you do not have administrator rights for your G-Suite account, please ask your system administrator.
- Click Apps > Google Workspace > Calendar
- Click on "External sharing options for primary calendars" and then on the pen behind "External sharing options for primary calendars".
- Select "All information is freely accessible, but external users cannot make calendar changes". This setting only defines the highest possible release level for users. So how far a user could publish his calendar. The calendars are not published automatically.
- Click on SAVE.
You can then see the home address in iCal format.According to Google, it may take up to 24 hours for these changes to take effect for all users.
VARIANT 2: Create a new calendar in the existing account