To Modify Quickbooks settings, go to Configuration > Company > Integrations and click on the highlighted Edit button:
This will take you to a screen that will allow you to modify these settings:
Add new customers to Quickbooks on invoice export -
Automatically create a customer in Quickbooks if none is found for a given Account invoice. OFF by default.
Add new Vendors to Quickbooks on bill export -
Automatically create a vendor in Quickbooks if none is found for a given Interpreter invoice. OFF by default.
Use expenses breakdown while generating invoices -
Qty and Rate for Fuel/Mileage and Travel Time expenses will be shown in the QuickBooks invoice. ON by default.
Use rate breakdown while generating invoices -
Create line item per rate applied. ON by default.
Allow Online Payments for Quickbooks invoices -
Allow Online payments for QuickBooks invoices. OFF by default.