In the General tab select General-> Select Applications->Option: QuickBooks.
Type. Select Invoice or Order if you want QuickBooks to synchronize your orders as Invoice or as an Order respectively.
Number Source. Select between Auto, OIS mobile request # and OIS Order #.
Number Prefix. When you want to specify the sequence you want your orders to have in QuickBooks.
Synchronize Statements: This option allows you to synchronize the history of open invoices, so the sales team can see them while they create the order for that customer.
Misc/Associations: in this section you will select the order of the information from your customers, go to the edit customer section of QuickBooks and make sure you have the info ordered as shown in the image, else, you need to change how the information is listed.