Web Apps do not have access to background location services. Hence, if the Delivery Application is running in the background or on a lock-screen, the live GPS data cannot be shared with the server.
If the delivery guy is on Point A, and the app is open, the location is shared with the server and the position of the delivery guy is shown to the customer on the Order Tracking page.
But, if the delivery guy locks the device and then drives, the customer will not receive the live location of the Delivery Guy.
If the delivery guy reaches Point B and then opens the app again, the customer will see a jump of the delivery live location from Point A to the new Point B on their Order Tracking page.