int relay=4;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  Serial.println("Hello, ESP32!");
  pinMode(relay,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
  digitalWrite(relay,HIGH);
  if(digitalRead(relay)==1){
    Serial.println("LED ON");
  }
  delay(500);
  digitalWrite(relay,LOW);
  if(digitalRead(relay)==0){
    Serial.println("LED OFF");
  }
  delay(500);
}