Setup Daily Sales under Home > Roster Settings > Daily Sales, then 'Edit'. Enter your Target sales for the day, then 'Done'.
These will be used to calculate the rostered Labour Cost as a percentage Sales, and show when the target Labour Cost/Sales has been exceeded (red dot in bar below dates).
To know if the Target Labour Cost/Sales have been exceed you must enter both the Daily Sales targets and the Labour Cost/Sales target.
How to setup Labour Cost/Sales target