15 minutes before your slot begins, you will receive a check-in notification. You should be able to simply confirm that you're available during the hours you have scheduled.
If your app freezes, or doesn’t work properly, follow the instructions below. If the first one doesn’t work, try the second one, and so on:
Check your internet connection, make sure it’s working properly
Close the app (from the background as well) and open it again
Power off your phone and turn it on again
If the problem persists, delete the app and download it again:
Download the app