When a hold becomes available for you, you'll receive an email and a notification in your library's OverDrive collection. You have three days to borrow the hold or have it delivered later if you're not ready to read it.

Delivering a hold later means you stay at the front of the wait list, but pass the current copy to the next person in line.

Find details at: https://help.overdrive.com/en-us/2265.htm