Apply discounts to pre-order product

Steps to manage:

1. From the admin page of the app, click on ” Single product ” tab
2. Select any of the pre-order products that you want to custom on the site
3. Scroll the page to payment and discount
4. Add the discount value for full-payment and partial payment ( You can select the type of discount as $ or %)
5. Click ” Save” to update the change