VBA - Named argument not found - vba

Question

Checking out https://wqweto.wordpress.com/2011/07/12/vb6-using-wininet-to-post-binary-file/ I get it how to upload a file, but I still need to add some additional parameters along the request, namely, _ID where this file should be put on server.
Currently I'm using code from first link:
Const STR_BOUNDARY As String = "3fbd04f5-b1ed-4060-99b9-fca7ff59c113"
Dim nFile As Integer
Dim baBuffer() As Byte
Dim sPostData As String
Dim pvPostFile As String
'--- read file
nFile = FreeFile
Open strPathFile For Binary Access Read As nFile
If LOF(nFile) > 0 Then
ReDim baBuffer(0 To LOF(nFile) - 1) As Byte
Get nFile, , baBuffer
sPostData = StrConv(baBuffer, vbUnicode)
End If
Close nFile
'--- prepare body
sPostData = "--" & STR_BOUNDARY & vbCrLf & _
"Content-Disposition: form-data; name=""uploadfile""; filename=""a.xls""" & vbCrLf & _
"Content-Type: application/octet-stream" & vbCrLf & vbCrLf & _
sPostData & vbCrLf & _
"--" & STR_BOUNDARY & "--" & _
"--" & STR_BOUNDARY & vbCrLf & _
"Content-Disposition: form-data; name=""_id"";" & vbCrLf & vbCrLf & _
"BFKrhMovy25DDemGE" & _
"--" & STR_BOUNDARY & "--"
'--- post
With CreateObject("WinHttp.WinHttpRequest.5.1")
.Open "POST", "https://api.backend.org/api/v1/upload/", False
.SetRequestHeader "Authorization: Bearer FbKl4KmuSdiXlk6PsWbvs9"
.SetRequestHeader "Content-Type: multipart/form-data; boundary=" & STR_BOUNDARY
.Send pvToByteArray(sPostData)
pvPostFile = .ResponseText
End With
MsgBox pvPostFile
Private Function pvToByteArray(sText As String) As Byte()
pvToByteArray = StrConv(sText, vbFromUnicode)
End Function
I'm getting "Named argument not found" in section
With CreateObject("WinHttp.WinHttpRequest.5.1")
not sure how to debug this :(
I have checked reference to Microsoft WinHTTP Services, version 5.1.
EDIT:
Problem was in SetRequestHeader, it needs two parameters following.
So correct code for SetRequestHeader lines is:
.SetRequestHeader "Authorization", "Bearer FbKl4KmuSdiXlk6PsWbvs9"
.SetRequestHeader "Content-Type", "multipart/form-data; boundary=" & STR_BOUNDARY

Answer 1

Main problem for me was understanding how parameters work in VBA, coming from total PHP environment..
So correctly setting .SetRequestHeader parameters and correctly putting together custom parameter with using two vbCrLf made all the difference.
With this solution, you can send as many params as you want now..