Get all flat product variants

curl --location 'https://platform.shopranos.eu/api/ProductVariants/flat?Price=&StoreId=&RetailPrice=&MaxPrice=&Size1=&Size2=&Size3=&Size4=&Size5=&Size6=&InsertDate=&UpdateDate=&Date1=&Date2=&Date3=&Date1DateRange=&Date2DateRange=&Date3DateRange=&InsertDateRange=&Search=&MinPrice=&Status=&Availability=&Tag=&SourceTag=&PrivacyRule=&Rule=&Condition=&Ids=&Skus=&Id=&PriceRange=&PriceRetailRange=&PriceMsrpRange=&BrandCode=&BrandId=&Attribute=&PathCategory=&CategoryId=&AdditionalCategoryId=&StockAvailabilityId=&AttributeSetId=&PriceCategoryId=&HasMedia=&MasterId=&AssortmentId=&CustomerId=&Page=&PageSize=&Sort='