ESP32 menggunakan talkback in thinkspeak iot platform V.1.2

#include <WiFi.h>
#include <ThingSpeak.h>

const char *ssid = "";
const char *password = "";
const char *talkbackAPIKey = "";

enum DevicePin {
  LED1 = 2,
  LED2 = 4,
  BUZZER = 5
};

WiFiClient client;

void setupDevice(DevicePin pin) {
  pinMode(pin, OUTPUT);
}

void connectToWiFi() {
  WiFi.begin(ssid, password);
  Serial.print("Connecting to WiFi");
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nConnected to WiFi");
}

void Setup_ThingSpeak() {
  ThingSpeak.begin(client);
}

void Logika_LED_dan_Buzzer(String command, DevicePin pin, const char* deviceName) {
  if (command == (String(deviceName) + "_on")) {
    digitalWrite(pin, HIGH);
    Serial.println("Response: 200, " + String(deviceName) + " ON");
  } else if (command == (String(deviceName) + "_off")) {
    digitalWrite(pin, LOW);
    Serial.println("Response: 200, " + String(deviceName) + " OFF");
  }
}

void setup() {
  Serial.begin(115200);
  setupDevice(LED1);
  setupDevice(LED2);
  setupDevice(BUZZER);
  connectToWiFi();
  Setup_ThingSpeak();
}

void loop() {
  ThingSpeak.writeField(talkbackAPIKey, 1, 0, "command", "check", "txt");
  delay(5000);
  String response = ThingSpeak.readStringField(talkbackAPIKey, 2, "string");

  if (response.length() > 0) {
    Logika_LED_dan_Buzzer(response, LED1, "LED1");
    Logika_LED_dan_Buzzer(response, LED2, "LED2");
    Logika_LED_dan_Buzzer(response, BUZZER, "BUZZER");
  } else {
    Serial.println("No response from TalkBack");
  }

  delay(10000);
}