To Set a Campaign Discount: Campaign > Page Styling section
1-Step Checkout Cart Page Example WITH Shipping Discount
One-page has all of the checkout information including payment method.
Notice that the 1-Step Checkout page has a Continue Shopping button
1-Step Checkout Cart Page Example WITHOUT Shipping Discount
2-Step Checkout Cart Page Example WITH Shipping Discount
Payment method is on the second page of the checkout process
Notice that the 2-Step Checkout page does NOT have a Continue Shopping button