Listing Mirror has the capability to cancel an order on Amazon from within Listing Mirror.
On the Order Details page, you will see this icon at the bottom.
Clicking on this icon will cancel the order on the marketplace. Doing so will NOT add that quantity from the order back to inventory. You will need to manually add the quantity back to your inventory, if applicable.
A Difference Worth Noting
Canceling an Amazon order DIRECTLY on the marketplace will result in Listing Mirror returning that quantity back to inventory automatically.
Canceling an Amazon order thru Listing Mirror will NOT add that quantity back to your inventory.