In order for Spectrum to import orders for manufacturing, there must be an indication that the line item is a customized item versus a stock item. The preferred method to do this is to create a custom line item property called "Recipe" (Note: name is configurable) to store the recipe identifier that is passed to Shopify via the Add to Cart process. This allows Spectrum to seamlessly process the order.
Relatedly, if following the product set up guidance, where the customization "add-on"/upcharge is configured as a unique variant, Spectrum recommends a line item property to associate the "add-on" with a line item. The recommended line item property name is "RelatedRecipe" (Note: name is configurable). The benefit to setting this property is that it allows Spectrum to fulfill all custom line items associated with the order automatically.