Steps to Void a Transaction
Voiding a Transaction request can be done when the batch isn't Closed yet, to preform this Action you will need to navigate from the Front Register>> Sales Tab that is located on the top right of your screen.
after you're in the current screen, simply click on the arrow icon, this will open the transaction details and Click on the Void button.
you will get a pop-up window to confirm that you want to Void a Transaction, again click on the "Void" button.
this will change your sales statues from Completed to Void,
Note that if your batch is closed you can use the Return items instead.