Post AR Invoice Group through code

Hi all,

I have read the above article.
But I don’t have any idea how can directly call the BO, not using the adapter.
My application server is 10.2.300.

I tried to use OData InvcGrpSvc to update “PostInProcess” : true.
But it will not post the invoice.

How can I Post AR Invoice Group through c# code?
Do anyone have some suggestion on it?
Thank you!

Epicor REST API, InvcGrpSvc > PostInvoices