Problem with ecg sensor and esp32 code

IoT Devices
,
1

The code below did not connect to the cloud. The code keeps failing. anybody should please help with the correct code or any corrections in the code?

#include <WiFi.h>
#include <PubSubClient.h>

#define WIFISSID “adextronics” // Put your WifiSSID here
#define PASSWORD “111111110” // Put your wifi password here
#define TOKEN “BBFF-fChAGEkTuGEeMgd07HWvYrIJgsFeeq” // Put your Ubidots’ TOKEN
#define MQTT_CLIENT_NAME “g59jy84usq” // MQTT client Name, please enter your own 8-12 alphanumeric character ASCII string;
#define VARIABLE_LABEL “sensor” // Assing the variable label
#define DEVICE_LABEL “esp32” // Assig the device label

#define SENSOR A0 // Set the A0 as SENSOR

char mqttBroker[] = “industrial.api.ubidots.com”;
char payload[100];
char topic[150];
// Space to store values to send
char str_sensor[10];
WiFiClient ubidots;
PubSubClient client(ubidots);

void callback(char* topic, byte* payload, unsigned int length) {
char p[length + 1];
memcpy(p, payload, length);
p[length] = NULL;
Serial.write(payload, length);
Serial.println(topic);
}

void reconnect() {
while (!client.connected()) {
Serial.println(“Attempting MQTT connection…”);

// Attemp to connect
if (client.connect(MQTT_CLIENT_NAME, TOKEN, "")) {
  Serial.println("Connected");
} else {
  Serial.print("Failed, rc=");
  Serial.print(client.state());
  Serial.println(" try again in 2 seconds");
  // Wait 2 seconds before retrying
  delay(2000);
}

}
}

void setup() {
Serial.begin(115200);
WiFi.begin(WIFISSID, PASSWORD);
// Assign the pin as INPUT
pinMode(SENSOR, INPUT);

Serial.println();
Serial.print(“Waiting for WiFi…”);

while (WiFi.status() != WL_CONNECTED) {
Serial.print(".");
delay(500);
}

Serial.println("");
Serial.println(“WiFi Connected”);
Serial.println("IP address: ");
Serial.println(WiFi.localIP());
client.setServer(mqttBroker, 1883);
client.setCallback(callback);
}

void loop() {
if (!client.connected()) {
reconnect();
}

sprintf(topic, “%s%s”, “/v1.6/devices/”, DEVICE_LABEL);
sprintf(payload, “%s”, “”); // Cleans the payload
sprintf(payload, “{”%s":", VARIABLE_LABEL); // Adds the variable label

float sensor = analogRead(SENSOR);

dtostrf(sensor, 4, 2, str_sensor);

sprintf(payload, “%s {“value”: %s}}”, payload, str_sensor); // Adds the value
Serial.println(“Publishing data to Ubidots Cloud”);
client.publish(topic, payload);
client.loop();
delay(500);
}