Are you getting below error while syncing orders to QBO?
You must select a product/service or an account for each split line with either an amount or a billable customer. You must enable shipping in your QuickBooks Online Company Preferences to post shipping charges.
Don't worry! you could fix the error by enabling shipping into your QBO. Here is a step by step process on "How to enable Shipping in QBO?"
Step 1 : Log in to your QuickBooks Online account and click on the gear icon to edit settings.
Step 2 : Now Click on Company Settings
Step 3 : On the Company Settings screen, go to Sales tab
Step 4 : Under the Sales from content area, select the Shipping checkbox, and click on Save
Once you have enabled shipping in QBO, you are ready to sync orders.