Setting up Invoice Sync Preferences
Shipping Charges
You can enable sync for shipping charges and select the corresponding charges from the product list. Xero doesn’t support direct sync of shipping charges, so you can add it as a product and then select it from the list to reflect the shipping charges of Shopify invoice in Xero.

Select the product from the drop-down dialogue box.
Invoice Creation
Select the Shopify order stage that triggers invoice/order creation for Xero–Fulfilled or Paid, Created.
Decide whether you want a draft order or a draft invoice, Awaiting-Approval Invoice, Awaiting-Payment Invoice, Paid Invoice and click "Save "

Invoice Field Mappings
Map the necessary fields from Shopify to Xero for invoice creation. You can create new fields in Shopify by clicking Create new Shopify field.
Click "Save Mappings" at the end.
