Send JSON Data with ESP32 over HTTP by WLAN -> no Answer

#include <WiFi.h>

#include <ArduinoJson.h>

#include <ArduinoHttpClient.h>

//#include <HTTPClient.h>

const char* ssid     = "XXXX";

const char* password = "XXXX";

//Create WiFi Object

WiFiClient client;

const char _ip_Adress[] = "XX.XXX.XXX.XXX";

String url = "POST";

int Length; 

void setup() 

{

  // put your setup code here, to run once:

  Serial.begin(9600);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) 

  {

    delay(500);

    Serial.print(".");

  }

  Serial.println("");

  Serial.println("WiFi connected");

  Serial.println("IP address: ");

  Serial.println(WiFi.localIP());

} //End Setup

void loop() {

  // put your main code here, to run repeatedly:

    StaticJsonBuffer<300> JSONbuffer;   //Declaring static JSON buffer

    JsonObject& JSONencoder = JSONbuffer.createObject(); 

    JSONencoder["DeviceId"] = "113";

    JSONencoder["Name"] = "JsonTest";

    JSONencoder["Serial"] = "5005191";

    JSONencoder["Token"] = "0";

    JsonArray& Index = JSONencoder.createNestedArray("Index"); //JSON array

    Index.add(1); //Add value to array

    JsonArray& Typ = JSONencoder.createNestedArray("Typ"); //JSON array

    Typ.add(1); //Add value to array

    JsonArray& Unit = JSONencoder.createNestedArray("Unit"); //JSON array

    Unit.add("%rh"); //Add value to array

    JsonArray& Value = JSONencoder.createNestedArray("Value"); //JSON array

    Value.add(32.4); //Add value to array

    char JSONmessageBuffer [512];

    JSONencoder.prettyPrintTo(JSONmessageBuffer, sizeof(JSONmessageBuffer));

    Serial.println(JSONmessageBuffer);

    //Create url

    url = "POST";

    url += " ";

    url += "/XXX/XXX.XXX.svc/";

    url += "UpdateDataJson";

    url += " HTTP/1.1";

    Serial.println(url);

    //Length output from Body -> used as Content Length

    Length = sizeof(JSONmessageBuffer);

    if (client.connect(_ip_Adress, 80))

      {

        //Send HTTP Header to Server

        client.println(url);

        client.println("Content-Type: application/json");

        client.println("HOST: " + String(_ip_Adress));

        client.print("Content-Length: ");

        client.println(Length);

        client.println("Connection: Close");

        client.println();

        //Send Json Data

        client.println(JSONmessageBuffer);

        //Check Answer

        String answer = client.readStringUntil('\r');

        Serial.println("Vor der Antwort");

        Serial.println(answer);

        Serial.println("Nach der Antwort");

        if (answer.startsWith("200 OK", 9))

        {

          Serial.println("HTTP: OK");

        }

      }

    delay(1000);  //Send a request every 1 second

}