DocuSign VBA Error 400 errorCode: ENVELOPE_IS_INCOMPLETE - docusignapi

Question

You help would be greatly appreciated to understand what then .setRequestHeader setting should be for this error.
Public Sub SignatureReq()
Dim httpRequest As MSXML2.XMLHTTP60
' defined request and result variables
Set httpRequest = New XMLHTTP60
' define the new URL for the signature request using the Base URL returned aboved appended with '/envelopes'
Dim sigURL As String
sigURL = URLBase & "/envelopes"
' currently sig URL is 'https://demo.docusign.net/restapi/v2/accounts/[account number]'
Dim Body As String
Body = "<envelopeDefinition xmlns=\" & Chr(34) & "http://www.docusign.com/restapi\" & Chr(34) & ">" + _
"<accountId>MyAccountID</accountId>" + _
"<status>sent</status>" + _
"<emailSubject>DocuSign API Call - Signature request from template</emailSubject>" + _
"<templateId>MyTemplateID</templateId>" + _
"<templateRoles>" + _
"<templateRole>" + _
"<name>Ronco</name>" + _
"<email>rolsen#myemail.com</email>" + _
"<roleName>Rono</roleName>" + _
"</templateRole>" + _
"</templateRoles>" + _
"</envelopeDefinition>"
Debug.Print Body
httpRequest.Open "POST", sigURL, False
httpRequest.setRequestHeader Body, "application/xml"
httpRequest.setRequestHeader "X-DocuSign-Authentication", Author
'httpRequest.setRequestHeader "Accept", "application/xml"
httpRequest.setRequestHeader "Content-Type", "multipart/form-data"
'httpRequest.setRequestHeader "Content-Type", "application/xml"
httpRequest.send
Debug.Print httpRequest.Status, "A"
Debug.Print httpRequest.statusText, "B"
Debug.Print httpRequest.responseText, "C"
Exit Sub
The response message is below. I understand the error is coming from the .setRequestHeader not being set correctly. Where can I find how the header and values are needed to be set for each .setRequestHeader that DocuSign will accept?
400 Bad Request { "errorCode":
"ENVELOPE_IS_INCOMPLETE", "message": "The Envelope is not Complete.
A Complete Envelope Requires Documents, Recipients, Tabs, and a
Subject Line. Content-Type does not contain boundary parameter." }

Answer 1

When sending a signature request from a Template the Content-Type for the API call needs to be set to either application/json or application/xml. It looks like you've currently got that commented out and are sending a multipart/form-data request. Comment that line out and add back in:
httpRequest.setRequestHeader "Content-Type", "application/xml"
If that doesn't work or you've already tried that I recommend enabling Request Logging through your developer account Preferences and examining the raw request that's being set to make sure your code is generating what you expect.