You can add "On-call" to an employee's shift by checking the box when creating the shift:
1 - Click on the preferred date and create the shift
2- When the pop-up window opens, go to the "Shift" section
3- Check the "On-call" box
3- Click on "Create"
N.B
Once the shift has been created and published, you will see the total hours for that day at 0. The hours will be adjusted once the clocking-in has been completed.
"On-call" will also be visible on the shift in the schedule: