Can't connect to Thingsboard server

Question

I installed the community version of Thingsboard and created a device, then sent data using the PC terminal and received data, but when I used MQTT Explorer, I sent data and Thingsboard did not receive it. Not only that, when I tried the Esp32 project also got an error that could not connect to Thingsboard server.

#include <DHTesp.h>
#include <WiFi.h>
#include <ThingsBoard.h>
#include <Arduino_MQTT_Client.h>

#define pinDht 15
DHTesp dhtSensor;

#define WIFI_AP "Wokwi-GUEST"
#define WIFI_PASS ""

#define TB_SERVER "thingsboard.cloud"
#define TOKEN "zQSkY28E5bisV4LyAKLY"

constexpr uint16_t MAX_MESSAGE_SIZE = 128U;

WiFiClient espClient;
Arduino_MQTT_Client mqttClient(espClient);
ThingsBoard tb(mqttClient, MAX_MESSAGE_SIZE);

void connectToWiFi() {
  Serial.println("Connecting to WiFi...");
  int attempts = 0;
  
  while (WiFi.status() != WL_CONNECTED && attempts < 20) {
    WiFi.begin(WIFI_AP, WIFI_PASS, 6);
    delay(500);
    Serial.print(".");
    attempts++;
  }
  
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("\nFailed to connect to WiFi.");
  } else {
    Serial.println("\nConnected to WiFi");
  }
}

void connectToThingsBoard() {
  if (!tb.connected()) {
    Serial.println("Connecting to ThingsBoard server");
    
    if (!tb.connect(TB_SERVER, TOKEN)) {
      Serial.println("Failed to connect to ThingsBoard");
    } else {
      Serial.println("Connected to ThingsBoard");
    }
  }
}

void sendDataToThingsBoard(float temp, int hum) {
    // Tạo đối tượng JSON
    StaticJsonDocument<256> data;
    data["temperature"] = temp;
    data["humidity"] = hum;

    // Gửi dữ liệu lên ThingsBoard (truyền cả đối tượng JSON và kích thước)
    if (tb.sendTelemetryJson(data, measureJson(data))) {
        Serial.println("Data sent successfully!");
    } else {
        Serial.println("Failed to send data!");
    }
}

void setup() {
  Serial.begin(115200);
  dhtSensor.setup(pinDht,DHTesp::DHT22);
  connectToWiFi();
  connectToThingsBoard();
}

void loop() {
  connectToWiFi();

  TempAndHumidity data =dhtSensor.getTempAndHumidity();
  float temp = data.temperature;
  int hum = data.humidity;

  Serial.println(temp);
  Serial.println(hum);

  if (!tb.connected()) {
    connectToThingsBoard();
  }

  sendDataToThingsBoard(temp, hum);

  delay(3000);

  tb.loop();
}

My project link: https://wokwi.com/projects/423607708915256321

I'm sure I've copied the right acces token !