Greetings from Site24x7.
The On-Call Schedule feature is available as part of the new updated version of Notification Profile. To migrate to the new profile,
Log in to Site24x7.
Navigate to Admin > Configuration Profiles > Notification Profile.
Click on the Migrate button on the top right side of the page.
Once you migrate, you can navigate to:
Admin > User Management > On-Call Schedule
Read more about the On-Call Schedule feature. Please feel free to share your feedback after trying the feature or contact firstname.lastname@example.org in case of any clarifications.