Rest API Get in AL Code?

Hi all,

how to do GET rest api in AL ?

I am using cloud BC?

Tested in Powershell with code no prob

#--------------------------------
function Execute-GetRequest 
#--------------------------------
( 
  [String] $URL
) 
{ 
  $WebRequest = [System.Net.WebRequest]::Create($URL) 
  $WebRequest.Headers.Add("X-IBM-Client-ID",  "f8c6f3f0-c644-49a9-9226-52002aed6d86")
  $WebRequest.Headers.Add("X-IBM-Client-Secret", "O8sH3cE1dY6cW2pR0wX3uA0vR7dQ1nF2sG0rQ1rN2yN7gT2sJ6")
  $WebRequest.ContentType = "application/json"
  $WebRequest.Method      = "GET"         

  try {
    $resp = $WebRequest.GetResponse() 
    $responseStream = $resp.GetResponseStream() 
    $Reader = [System.IO.StreamReader]($responseStream) 
    $ReturnXml = $Reader.ReadToEnd() 
    $responseStream.Close() 
    return $ReturnXml 
  } catch {
    Write-Error $Error[0]
  }
}

#----------------------------------------------------------------------------------------------------------------------

$url = "https://************/CorpPassAuth?callback_url=https://businesscentral.dynamics.com/sandbox&tax_agent=false&state=State&scope=GSTF7SubCP"

$ret = Execute-GetRequest $url
$ret

I used this in BC, failed

 procedure CallBusinessCentralAPI()
    var
        Client: HttpClient;
        ResponseMSg: HttpResponseMessage;
        Url: Text;
        RequestHeaders: HttpHeaders;
        RequestBody: Text;
        RequestContent: HttpContent;
        RequestMsg: HttpRequestMessage;
        Result: Text;
    begin
        RequestHeaders := Client.DefaultRequestHeaders();
        //RequestHeaders.Add('Authorization', GetAuthenticationHeaderValue(AccessToken));
        RequestHeaders.Add('X-IBM-Client-Id', 'f8c6f3f0-c644-49a9-9226-52002aed6d86');
        RequestHeaders.Add('X-IBM-Client-Secret', 'O8sH3cE1dY6cW2pR0wX3uA0vR7dQ1nF2sG0rQ1rN2yN7gT2sJ6');
        RequestHeaders.Add('Accept', 'application/json');
        RequestContent.WriteFrom(RequestBody);
        RequestContent.GetHeaders(RequestHeaders);
        Url := 'https://******************/CorpPassAuth?callback_url=https://businesscentral.dynamics.com/sandbox&tax_agent=false&state=State&scope=GSTF7SubCP';
        RequestMsg.GetHeaders(RequestHeaders);
        RequestMsg.SetRequestUri(Url);
        RequestMsg.Method('GET');

        Client.Send(RequestMsg, ResponseMSg);
        // Read the response content as json.
        ResponseMSg.Content().ReadAs(responseText);
        Message('%1', responseText);
    end;

it returns me html instead of json

any advise?

Thanks