Hi finance124,
We can provide information on how to post sales in QuickBooks Online or (for example) guide you to change the income account for a product/service item if you want to record these to different accounts, however we are unable to advise on how third party apps integrate with QuickBooks Online or what limitations these have and why. As these apps are built and maintained by these third parties we would suggest you reach out to their support for questions regarding integration. On Unleashed Software's page in the App Store, they have both a support website and contact number with which you can reach out to them and determine why the application has an option to change the Cost of Goods Sold account but not the Sales account. You can also refer to the Intuit Developer website if you want to look further into app developments and APIs.
-Kass
