Updates a discount rule.
Each time the discount rule is updated, revision increments by 1. The existing revision must be included when updating the discount rule.
This ensures you're working with the latest discount rule information, and it prevents unintended overwrites.
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.