Creates a new coupon.
When creating a coupon, the specification object must contain values for name, code, startTime,
and either scope or minimumSubtotal. The exception is for a freeShipping coupon type, for which you cannot apply
a scope and minimumSubtotal is optional.
The coupon scope defines the items a coupon applies to. A coupon can apply to all items in a specific Wix application,
a group within the application, or a single item within a group.
See valid scope values.
The specification object must also contain a value for exactly 1 of the following coupon properties.
This defines the coupon type.
"moneyOffAmount""percentOffRate""freeShipping""fixedPriceAmount""buyXGetY"You can only call this method when authenticated as a Wix app or Wix user identity.
This method doesn’t return any custom errors, but may return standard errors. Learn more about standard Wix errors.