The Add Custom Sale action lets you add a custom amount to the cart, either by opening the custom sale dialog box where the cashier enters a custom label and price, or by automatically adding a fixed, preconfigured sale each time the action runs. Fixed custom sales can also apply taxes using the outlet’s default rates. This action is ideal when an item isn’t in the catalog, such as donations, service fees, or uncategorized sales.
If you want to customize the Custom Sale dialog box, use the Custom Sale element instead since the action triggers a pre-built pop up.