solved - XML request to REST api

I wrote this sample code to get the Elektron Timeseries Extraction request for a sample ISIN instrument. You can take it as a starting point and implement your own. You will need a valid authentication token which can be retrieved by invoking the https://hosted.datascopeapi.reuters.com/RestApi/v1/Authentication/RequestToken endpoint.

Sub ExtractWithNotes()

    Dim mxm As Object
    Dim requestMsg As String
    Dim response As String
    Dim authToken As String
    
    authToken = "***"
    
    requestMsg = "{""ExtractionRequest"": {""@odata.type"": ""#ThomsonReuters.Dss.Api.Extractions.ExtractionRequests.ElektronTimeseriesExtractionRequest""," & _
        """ContentFieldNames"": [""Ask"",""Bid"",""High"",""Last"",""Low"",""Trade Date""]," & _
        """IdentifierList"": {""@odata.type"": ""#ThomsonReuters.Dss.Api.Extractions.ExtractionRequests.InstrumentIdentifierList""," & _
        """InstrumentIdentifiers"": [{""Identifier"": ""US0378331005"",""IdentifierType"": ""Isin""}]," & _
        """ValidationOptions"": null,""UseUserPreferencesForValidationOptions"": false}," & _
        """Condition"": {""StartDate"": ""2015-12-01T13:00:00.000Z"",""EndDate"": ""2015-12-02T13:05:00.000Z""}}}"
    
    Set mxm = CreateObject("MSXML2.XMLHTTP")
    
    Debug.Print "Sending Request..."
    
    With mxm
        .Open "POST", "https://hosted.datascopeapi.reuters.com/RestApi/v1/Extractions/ExtractWithNotes", True
        .SetRequestHeader "Authorization", "Token " & authToken
        .SetRequestHeader "Prefer", "respond-async"
        .SetRequestHeader "Content-Type", "application/json; odata=minimalmetadata"
        
        .Send (requestMsg)
        ' waiting for response
        While mxm.readyState <> 4
            DoEvents
        Wend
        response = .ResponseText
    End With

    Debug.Print response

End Sub