Your app should be open in the background (with location tracking enabled) to allow the client to track your estimated time of arrival to the booking (ETA). By enabling location tracking, the client will be able to prepare for your arrival to the booking.
When you arrive at the correct location of the shift, you will be able to clock in to indicate the start time of your job. This will allow the payments system to update and ensure that you are paid correctly for the time you are at the job.
Your location is confidential and is never shared with third parties.