Toggl by Apigrate works with QuickBooks Online Plus. The app does not work with QuickBooks Desktop or QuickBooks Enterprise.

The QuickBooks Online Plus product has the time tracking feature that you need to keep track of billable time entries for invoicing. If you're curious about whether your version of QuickBooks Online has this feature, you can open up any customer in QuickBooks and then pulll down the drop-down menu on the upper right. You should see a "Time Activity" link like this: