Zoho Books - Vendor Portal - API

Zoho Books - Vendor Portal - API

Hi, How I can access (API) to documents uploads by vendors at the vendor portal?
At the Invoice section of documentation nothing tells about files in pending (without a Invoice created)
https://www.zoho.com/books/api/v3/#Invoices_List_invoices

I want to get a list of documents on "Pending" status uploaded by my vendors.

Thanks