byte led_state = 0;
void IRAM_ATTR Ext_INT1_ISR()
{
  if(led_state == 0){
    led_state = 1;
    digitalWrite(35, HIGH);
  }
  else{
    led_state = 0;
    digitalWrite(35, LOW);
  }
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(2, OUTPUT);
  led_state = 0;
  digitalWrite(2, LOW);
  pinMode(35,INPUT_PULLDOWN);
  attachInterrupt(35, Ext_INT1_ISR, RISING);
}

void loop() {
  // put your main code here, to run repeatedly:
  delay(10); // this speeds up the simulation
}