int led =2;
int btn =4;
void setup() {
 
  pinMode(2, OUTPUT);
  pinMode(4, INPUT);
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
}

void loop() {
  //delay(10); 
  if(digitalRead(4)==HIGH){
    digitalWrite(2, HIGH);
    Serial.println("LED IS ON ..");
    //delay(500);
  }
  else{
    digitalWrite(2,LOW);
  }
}