Apply Discount Code to Checkout Automatically
/r/checkout?myshopify_domain=bootstrap-dev.myshopify.com&cart_token=5566cd50a07c3c944f9b4d42524f5f98<b style="background-color: initial;">&discount=HALFOFF
Note: This feature does not work if the discount code is configured to only apply Once Per Customer, since that would match by email. If the discount is automatically applied, there is no email and this does not apply. If you must have One Per Customer enabled, then the best solution to fit your needs would require a totally custom built system that applies discounts to orders post-purchase. This would require access to our API.