void notFound(AsyncWebServerRequest *request)
{

  digitalWrite(online, HIGH);   //turn-on online LED indicator

  if (! request->url().endsWith(F(".TXT")))
  {
    request->send(404);
  }
  else
  {
    if (request->url().endsWith(F(".TXT")))
    {
      //.endsWith(F(".txt")))

      // here comes some mambo-jambo to extract the filename from request->url()
      int fnsstart = request->url().lastIndexOf('/');

      fn = request->url().substring(fnsstart);

      PATH = fn;

      accessLog();

      Serial.print("File:  ");
      Serial.println(fn);



      File webFile = SPIFFS.open(fn);

      Serial.print("File size: ");

      Serial.println(webFile.size());

      if (!webFile)
      {

        Serial.println("File:  " + fn + " failed to open");
        Serial.println("\n");

      }
      else if (webFile.size() == 0)
      {

        webFile.close();

      }
      else
      {

        //request->send(SPIFFS, fn, String(), true);  //Download file
        request->send(SPIFFS, fn, String(), false);  //Display file

        webFile.close();

      }

      fn = "";

      end();



    }

  }

  digitalWrite(online, LOW);   //turn-off online LED indicator

}