Zoho Books Invoice Update API

Zoho Books Invoice Update API

Hi there,

I have been trying to update invoice in Zoho Books through API once the invoice is sent to customers but I received the error message like
"{"code":110701,"message":"Please enter the reason for updating a sent invoice."}".

I had a look at Zoho Books API but I didn't find any field to enter reason for same.

Could you please let me know which field to use.?

Thanks