Coupon in the URL: ?coupon= or ?couponCode=
When your product has active coupons, the checkout page shows a coupon field. You can pre-fill it from the query string.
Create coupons in the merchant app (per product): code, discount type, value, validity, and usage limits as supported by your dashboard.
If the checkout URL contains coupon=CODE or couponCode=CODE, the field is filled automatically when the page loads (up to 40 characters). The customer can still edit or clear it. The coupon field is only visible when the product has at least one active coupon.
The code is sent when the customer submits the form. The server validates it: inactive, expired, or invalid codes return an error and the order is not created.
Combine with other parameters using & — for example language and UTMs.
Sample links
Replace the sample product id with your real product id from the dashboard. Replace the product id and LAUNCH10 with real values. In HTML attributes, use & between parameters.
https://pay.zenofy.io/p/507f1f77bcf86cd799439011?coupon=LAUNCH10
https://pay.zenofy.io/p/507f1f77bcf86cd799439011?couponCode=LAUNCH10&lang=pt