Project Transactions Debit and Credit Accounts - Assigned by Nonstock items

I have an operating system which is where the trigger logic for all service fees resides. Example: New File is authorized, billing policy is selected, billing policy contains the fee amount for that client. This operating system is the “source of truth” and Acumatica is used for client invoicing through the projects module. Operating system creates a “fee voucher” that contains the information needed on the Acumatica project transaction. Is there a way for the nonstock item to provide the debit and credit accounts for the project transaction? I can manually enter them when I create a transaction. Wondering the best way to accomplish this with an API/Integration.