Go to MANAGE MY BUSINESS->MANAGE ROLE SHIFTS PREMIUMS
You will see a list of created shift premiums.

To add a new shift premium, click ADD. To edit a shift, select EDIT on the row of the shift premium. Provide a name, icon and type.
HOURS – this means for any shift, the amount of hours assigned will be added to RT hours
PAY – this means for any shift, the amount of pay will be added to their total (ex. A shift may have a $100 bonus for working overnight)