If you arrive at the shift location on time and get clocked in, Traba guarantees a minimum pay of 4 hours. If the shift is cut short, you will be paid only for your time worked, or 4 hours, whichever is greater, not the full shift pay.
The entire shift time is a best estimate made by the business posting the shift and it is subject to change. Similarly, it is often possible that a shift goes on longer than posted on the app and in this scenario, you will earn more than the full shift pay.