If you'd like to set up individual item special price on online ordering, please refer to the following steps and modify in backhouse :
Login Backhouse > Online Menu > Menus Schedules
Find the menu you want to set up and click on "Edit."
In the menu, locate the item you want to apply a discount to and enter the "Special Price" separately for "Takeout" and "Delivery", click "Publish":
It will show as below on the ordering page:
