Calling External HTTPS RestService using RestClient.NewSecure ?

Hi All,

Has anyone successfully used restClient.NewSecure (preferred) (also tried sockets,  but connection closed error there) to successfully call an https service (specifically azure cognitive services), and if so, could you give me a pointer on what is wrong with my code? Attached is a java routine that works perfectly (DetectLanguage) obviously with a valid key for ACS , but if I try and run what I believe to be the equivalent in the code in Oscript below using RestClient, I get an authentication failure. (Missing access token - but all that should need to be provided is the subscription key that works when called from java using DetectLanguage code. 

function CallRestClient()
   String hostname = "ottextanalytics.cognitiveservices.azure.com"
   Integer port = 443
   Integer timeout = 200
  Assoc params
  List docHeaders={'countryHint','id','text'}
  Recarray docArray = RecArray.Create(docHeaders)
  Assoc documents
  String jsonContent, body
  Integer bodyLen = 0
  Assoc retVal

      //Create connection
      RestClient acsClient=RestClient.NewSecure(hostname, port,\
                                                                             baseURI, timeout)
      
     //Populate parameters
      params.("Ocp-Apim-Subscription-Key")="xxxxxxxxxxxxxxxxxx"
      params.("Content-Type")="text/json"

      //Create JSON content
     RecArray.AddRecord(docArray,{'US','1','Hello World'})
     jsonContent = web.ToJSON(docArray)
     documents.documents = jsonContent
     body = web.ToJSON(documents)
    bodyLen = Length(body)

   // Submit request
   retVal = acsClient.Post( params, body, bodyLen)
   echo(retVal)       
end

Most appreciated if anyone can spot where this is going off the rails

Cheers

Iain