We discourage professionals from canceling a confirmed job. A high cancellation rate can impact your job prospects.
However, we know that emergencies do happen. If you're using the app to cancel, go to My Jobs, then tap on Upcoming jobs. Your job should be listed there. Find it, tap it, and then hit Cancel at the bottom of the job window.
To cancel a job on the Web Portal, click on the Scheduled Jobs tab and then click on the job post. Doing so will open a job details window. Just click Cancel at the bottom of the window to let the facility know you're unable to make your shift.