You can optionally set weintegrate to track classes for items in QuickBooks Online, which will be added to your sales receipts when integrating Shopify orders into QBO.
To select this option, click the checkbox labeled ‘Track classes in QuickBooks Online’, which will cause the Class field and corresponding dropdown to appear. Via the Class field dropdown list, select from the appropriate value of classes and sub-classes that have been pre-loaded from your QuickBooks Online company.
Click here to learn about Converting Inactive Items to Active when integrating Shopify with QuickBooks Online.