Choose the header text and select the Specials and Discount icon which is a little hard to see but it should be the last icon in the list below and it has the price tag icon in the middle of the circle.
To create a special go to the Specials tab on the left navbar menu. Click New Special, add a title and subtitle. Those will appear on the left side of the special card. The right side will be wysiwyg content. This is a slider component that will show one card at a time.