Zoho Expense - Update Expense Report through web API

Zoho Expense - Update Expense Report through web API

Hello,

I am currently having issues updating fields in expense reports (not individual expenses) through the API as described in the API documentation. When I make that request using the invokeAPI Deluge function, I receive a response from the API saying {"code":37,"message":"The HTTP method PUT is not allowed for the requested resource"}

Am I supposed to use the POST method even if the expense report already exists, or is there something else wrong with my request?

Thanks in advance, 

Luca