As an employee, you can see your scheduled extra hours under Attendance > Time & Pay Adjustments which you can accept or reject.
Apart from this, you can also -
See the name of the manager who assigned the instruction.
View any comments made by the manager.
For Non-shift employees, extra hours instructed are automatically shown with the new check in/check out time.
For Shift employees,
Extra hours instructed are shown with the new check in/check out time under My Schedule.
The upcoming section shows shifts that have extra hours.