Transactions - Applying a Discount
To do a discount at an item level: once you select an item from the menu there will be the option to add a discount and then you can choose whether or not you want it to be reflected as a dollar amount or percentage.
To add a basket level discount: click on the Add Discount button in the bottom right hand corner of the page when checking out an item.
A new window will pop up and you can either select a custom discount that you created or set a dollar or percent discount for the whole cart.