Vendor Signatures Needed for Purchase Orders

Vendor Signatures Needed for Purchase Orders

Hello everyone,

We have a unique requirement that necessitates that Vendors & Suppliers formally acknowledge our Purchase Orders upon receipt. I was hoping that there would be an option to do so in Zoho Books, but that does not appear to be the case. Does anyone know of a function or script that allows Zoho Sign to be integrated with Books for vendor PO signatures/acknowledgements, the way it is available for Customer Quote signatures? 

I mocked up something to illustrate what we are looking for.

Any help would be appreciated.