QuickBooks
ODBC
As of January 2023, the StarfishETL Connector for for QuickBooks On-Premises utilizes the QODBC Driver for QuickBooks: https://qodbc.com/what-is-qodbc/
The Starfish Connector requires the "QODBC Driver Server Edition" so there is an additional one-time cost of $499 from QODBC. There is a 30 day free trial available for testing. See https://qodbc.com/qodbc-versions-differences/ for information about each QODBC edition.
As of April 2023, I've been using the QODBC Connector with a customer for several months and we have found it to be much more stable than the old version.
Connection to QuickBooks
To Connect to QuickBooks, please see the documentation from QODBC: https://qodbc.com/connecting-to-quickbooks/