If you need to disable an existing discount code in Cashier, you can do so by following these steps:
- From "Shopify Admin", select Apps.
- Select Cashier.
- Select Discount Codes.
- Select View Discount Codes.
- Select Disable next to the discount code to disable.
Note: This changes the "Disable" button to read "Enable", clicking it again will re-enable the discount code.