Retrieves a discount rule.
The getDiscountRule() function returns a Promise that resolves when the specified discount rule is retrieved.
This method may require higher-level permissions than the caller has, based on their identity and roles and permissions. In these cases, you can ensure the method is called with the required level of authorization by using one of the following:
ID of the discount rule to retrieve.
This method doesn't return any custom errors, but may return standard errors. Learn more about standard Wix errors.