Old API has this implemented by simply not actually processing the payment. New payment popup currently shows "Invalid positive integer" error when trying to process 100% discount payment. So it should be made similar to old API - e.g. not try to actually charge the customer when 100% discount coupon is applied.
Old API has this implemented by simply not actually processing the payment. New payment popup currently shows "Invalid positive integer" error when trying to process 100% discount payment. So it should be made similar to old API - e.g. not try to actually charge the customer when 100% discount coupon is applied.