When using MyWorks Sync, you may see the QuickBooks product "Default for Unmatched Products" - either used in an order we sync to QuickBooks, or in a setting in MyWorks Sync > Settings > Default.
This is the name of a product that MyWorks will create in your QuickBooks Online company when MyWorks is first connected.
In short, this product/setting is meant to be used only for orders that contain a Shopify product that is not mapped to a corresponding product in QuickBooks.
While the above setting can be changed to use any other default/general sales product in your QuickBooks that you'd like to be used instead - this setting is only used if MyWorks is syncing an order to QuickBooks that contains a product that's not mapped together.
You can check and assign product mappings easily in MyWorks Sync > Map > Products.