Draft Order and Discount Code Explanation
Draft order and Discount Code options are introduced to resolve the case when a merchant wants the discount offered by the third party app together with the discount applied from our app.
Draft Order: This is the first and old way to create a bundle products order.
Here are few points which are considered in the case of Draft Order:
a. Product inventory can’t be handled in the draft order.
b. App will create a draft order and here is how it will appear in orders section

c. You cannot track draft orders in Google Analytics or Facebook pixel.
d. The draft order method does not support multi-currency.
e. In Draft order, bundle discount will be displayed on the checkout page as in the below image

Discount Code: In the case of Discount code, shopify's discount method is used in the app.
Here are few points which are considered in the case of Discount Code:
a. Shopify totally handles the product inventory.
b. You can track the orders in Google Analytics or Facebook pixel in the case of discount
code.
c. If you are using multi-currency then use the Discount Code method.
d. A discount code will be generated with the discounted amount and a discount
code will be applied at checkout page.

e. App will not create a draft order in the case of discount code.