Access (and authenticate at) Zendesk web API with Excel VBA - json

Question

I'm trying to use a web API with Excel VBA.
In the API instructions it is written:
Using cURL
curl https://{subdomain}.zendesk.com/api/v2/users/create_or_update.json \
-d '{"user": {"name": "Roger Wilco", "email": "roge#example.org"}}' \
-H "Content-Type: application/json" -X POST \
-v -u {email_address}:{password}
Link to the API itself (Create or Update User) https://developer.zendesk.com/rest_api/docs/support/users#create-or-update-user
This is my code:
Public Function PostJsonRequest() As String
Dim strURL As String
Dim strParse() As String
Dim jsonStr As String
Dim hreq As Object
Dim tixScript As Object
On Error GoTo Er
Set hreq = CreateObject("MSXML2.XMLHTTP")
strURL = "https://subdomain.zendesk.com/api/v2/users/create_or_update"
hreq.Open "POST", strURL, 0, "username/token", "token"
hreq.setRequestHeader "User-Agent", "Chrome"
hreq.setRequestHeader "Content-Type", "application/json"
hreq.setRequestHeader "Accept", "application/json"
hreq.setRequestHeader "-v -u {MyEmail}:{MyPassword}"
jsonStr = "-d '{""user"": {""name"": ""Roger Wilco"", ""email"": ""roge#example.org""}}'"
hreq.Send jsonStr
MsgBox hreq.responseText
Exit Function
Er:
MsgBox "Error - " & Err.Number & " - " & Err.Description
End Function
In the Email and Password line I get this error:
Error - 450 - Wrong number of arguments or invalid property assignment

Answer 1

This is not valid hreq.setRequestHeader "-v -u {MyEmail}:{MyPassword}"
Try basic authentication instead
hreq.setRequestHeader "Authorization", "Basic dXNlcjpwYXNzd29yZA=="
where dXNlcjpwYXNzd29yZA== is the base64 encoded {MyEmail}:{MyPassword} string.
For example:
Dim username As String
username = "user123"
Dim password As String
password = "abc123"
hreq.setRequestHeader "Authorization", "Basic " & EncodeBase64(username & ":" & password)
Where the base64 encoding function works like this:
Private Function EncodeBase64(ByVal plainText As String) As String
Dim bytes() As Byte
Dim objXML As Object 'MSXML2.DOMDocument60
Dim objNode As Object 'MSXML2.IXMLDOMNode
bytes = StrConv(plainText, vbFromUnicode)
Set objXML = CreateObject("MSXML2.DOMDocument.6.0")
Set objNode = objXML.createElement("b64")
objNode.DataType = "bin.base64"
objNode.nodeTypedValue = bytes
EncodeBase64 = objNode.Text
Set objNode = Nothing
Set objXML = Nothing
End Function
Also make sure you only send the JSON part without the -d '…':
jsonStr = "{""user"": {""name"": ""Roger Wilco"", ""email"": ""roge#example.org""}}"
Finally a more cosmetic thing than an issue:
hreq.setRequestHeader "User-Agent", "Chrome"
Either set your user agent string to fake a real user agent, for a current chrome it would look like:
Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/88.0.4324.150 Safari/537.36
Faking a user agent is to make the website think you are surfing with a Chrome for example. For the API this is not necessary I guess, so you can set it to something generic like:
hreq.setRequestHeader "User-Agent", "MyVBAProject Version x.y.z Windows 10 using MSXML2.XMLHTTP"
to show the website clearly which type of application you are.
At least don't set it to "Chrome" as this is just confusing as Chrome would never use that user agent.