How to VOID
Select the Orders/Items and click the Burger Icon on the upper right portion of the screen. Then click and select VOID.
Then Select the items that you need to Void.
Then Click next.
Select a reason for voiding. Then click OKAY.
After the last step, the screen will automatically go back to the New Sale view. The one with the dark grayed color background indicates that it was voided and with a label VOIDED on the lower part of the product name/order name.