trigger a draft invoice creation

trigger a draft invoice creation

Hello,

Context: 

Zoho Inventory is used to manage orders, invoices and payments. 
Sales channels are:
-Zoho Form that triggers unpaid sales orders creation in Zoho Inventory
-Zoho Commerce that triggers paid sales orders creation in Zoho Inventory
-Manual order creation that triggers unpaid sales orders creation in Zoho Inventory

At the exact moment an unconfirmed or draft order is created in Zoho Inventory, I need an draft invoice to be created as well in order to replicate the sales order number in the invoice number field. I just add an "F" in front of the number. *

*Seems to me that this is easily doable through Zoho Flow. ( "F" + ${trigger.salesorder_number} )

This way, sales order numbers are always the same as invoice number. Makes operations and follow-ups easier. 

Problem:

I can't find a way to trigger invoice creation WHEN THE SALES ORDER IS DRAFT OR UNCONFIRMED. 
At first, I did found a way to almost reach my goal. I found the Sales Order Cycle settings to get an invoice automatically created when a new (confirmed) sales order is created. I tough this option with similar transaction number series could do the trick but I was wrong. In this business context, there could be invoice duplication or creation alone... without sales order, so this make the transaction number series desynchronize quickly or just broke the ascending order for transaction number series. (or maybe I resolve this part by blocking all invoice creation alone? Always go through sales order for any type of transactions?...)

I could decide to make sales order confirmation triggered each time a new sales order is created... but the draft sales order is an important step because we can add items, transport fees and update other stuff (in both invoice and sales order) when the sales order is unconfirmed or draft... but this is not possible when the sales order is confirmed.  

So, to summarize the main goal is: 

-For every sales order created, it need to stay draft or unconfirmed, then trigger a draft invoice creation with the modified invoice number based on sales order number. 

Do you have any magic trick for me? 

Thanks!