promotionId

Promotion identifier, which is the final component of name. For example, this field is "free_gift", if name is projects/*/locations/global/catalogs/default_catalog/promotions/free_gift. The value must be a UTF-8 encoded string with a length limit of 128 characters, and match the pattern: a-zA-Z*. For example, id0LikeThis or ID_1_LIKE_THIS. Otherwise, an INVALID_ARGUMENT error is returned. Corresponds to Google Merchant Center property promotion_id. */