how to API post a draft invoice with discount

[Animal_Kingdoms]

So a "known" issue that has no time frame for solution is draft orders greater than 100 lines can not get a discount - it errors our.

Supports solution is to do multiple invoices, but in our case that would mean 4 invoices.

Our customer requires one as it is part of a purchase order request that needs one invoice.

Can someone provide some guidance on using API Post to upload a draft invoice with discounts (flat 5%) 

I have an export of the saved draft order (without the required discount) and google sheets with API connector

Support could not even confirm if this would work if attempted!

[SBD_]

Here are some examples, the fourth example shows a flat percentage discount.

In a recent update, the 'amount' is automatically calculated if you don't provide it.