QuickBooks doesn't have "Projects" in CMIS's sense of the term, but they do have Jobs that can be placed under a "Customer". In order for this integration to work there must be a Client that is in QuickBooks assigned to the Project that will be sent to QuickBooks.
Navigate to Projects > General
From Actions select Send To QuickBooks
NOTE: Once a project has been sent it is assigned a QuickBooks identification at Projects > General > Support named QB Project List ID