For the bulk export of orders in QuickBooks Online, you need to do following steps :                                                   

  1. Enable bulk orders export settings in basic settings tab.                         
  2. You will get Export to QuickBooks option in order bulk options in order listing page.                        
  3. Select orders that you want to export and then select Export to QuickBooks option in bulk actions list.          
  4. All orders is exported successfully in QuickBooks Online.