POS Custom discount
Add a custom discount (new discount) on Shopify POS along with store credit.
1- After selecting the customer and the order that you want to give the discount, click on the Items button to open cart.
2- Choose the items you want the discount to be applied to and click “Add discount to item”.
3- Set the amount of the discount and the discount title.
4- Click Save
Please check this step-by-step video: