QuickBook

 Quick Book API : https://developer.intuit.com/app/developer/qbo/docs/api/accounting/all-entities/item#query-an-item

 Get Access Token :- https://developer.intuit.com/app/developer/playground

 Ref : https://www.youtube.com/watch?v=F5_6-21GaxM

Web Service to add in Web Connector : https://www.c-sharpcorner.com/article/how-to-integrate-quickbooks-desktop-using-web-service-qbxml/

Quickbook Sample Application : https://developer.intuit.com/app/developer/qbdesktop/docs/develop/sample-applications-and-code

SalesOrder : https://quickbooks.intuit.com/learn-support/en-us/other-questions/quickbooks-desktop-sales-order-transaction-date-setting/00/1025666