Hello,
CF :
www.hikashop.com/support/documentation/1...ugins-coupongen.html
Coupon template
The Discount coupon id is the id of the HikaShop coupon that would be used as template.
Your coupon have to be unpublished. When the plugin would duplicate the coupon, it would automatically published it (and set the "used times" to zero).
The documentation indicates that you need to create an HikaShop coupon in the HikaShop backend.
Not by just open the URL, but by using the HIkaShop interface in the discount/coupon section and create entirely a new coupon.
Once you have a coupon in HikaShop, you will be able to select it in the HikaSerial coupon generator.
Regards,