How to get the tax spliting functionality using BAPI_ACC_DOCUMENT_POST

Hi Experts,

In FB01 tcode when we post the invoice separate tax line item is getting created automatically.

But we are posting invoice with BAPI_ACC_DOCUMENT_POST here it is not happening.

Before posting this question here found a thread https://scn.sap.com/docs/DOC-43262.

Here from the thread info we implemented the BADI and enabled the tax calc flag and implemented the exit.

Still the separate tax line item is not getting created.

Can any one please clarify how we can acheive that functionality.

Thanks in advance.

kind regards,

Shiva