Nice to have you in the Community space, @FlyingBull.
You can run the Transaction Detail by Account in your QuickBooks Online (QBO) account and customize it to have the QTY and Rate column. I’d be glad to walk you through the steps.
- Go to the Reports menu.
- Type in and enter Transaction Detail by Account.
- Click the Customize button.
- Select Rate and QTY from the Rows/Column drop-down.
- From the Filter drop-down, select Transaction type and choose Invoice from the drop-down.
- Then click Run report.

You can also check this article for additional steps: Customize reports in QuickBooks Online.
Once done, you can now export the report and import it to your Fintech account. Moreover, you might also want to check this link for reference in case you need to import your data to QBO: Common questions about importing data to QuickBooks Online.
In case you have other questions or concerns about importing or exporting data from QuickBooks, let me know in your reply. I’ll be around to listen and back you up. Have a great day!