Variants in Shopify can have the same SKU or a blank SKU.
In Spark Shipping, all products are required to have a unique Product SKU.
In the case where Shopify variants do not have a unique SKU, Spark Shipping will add this extra ID after the SKU.
To correct this we would recommend that you can update the Vendor SKUs in Spark Shipping to match the actual vendor SKUs.
How do I add variant items?
- This has to be done on the Shopify side
- All SKUs in Spark come over as single SKU
Below is an article that will help you get started building variants in Shopify: