Pallet Connect is able to directly connect to Quickbooks Online. For Customers using Quickbooks Desktop however, there is not a direct connection. Therefore, Transaction Pro is needed to easily import Invoices, Purchases and Credit Memos into Quickbooks.
At time of writing, Transaction Pro requires a one time set up fee at purchase. Transaction pro connects directly to Quickbooks desktop. The user will upload the Pallet Connect csv. file to Transaction Pro, and it then updates Quickbooks.
Pallet Connect's CSV files are already formatted for Transaction Pro. To download the file, go to Export Data > Transaction Pro.
select the date range and type of transaction
Once the list of transactions for the date range selected appear on the screen, click on Export Selected Transactions.
Click Yes (Clicking No will not prevent the transactions from importing, just not mark them). 
Click Bell Icon to download, then "please click here".
Use this file to import information to Quickbooks using Transaction Pro. Here are some helpful links and videos from the Transaction Pro support portal.