int btn1 = 15;
int btn2 = 2;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");

  pinMode(btn1, INPUT);
  pinMode(btn2, INPUT);
}

void loop() {

  bool btn1_state = digitalRead(btn1);
  bool btn2_state = digitalRead(btn2);

  if (btn1_state == HIGH){
    Serial.println("Button 1 is pressed");
    delay(200);
  }

  if (btn2_state == LOW){
    Serial.println("Button 2 is pressed");
    delay(200);
  }
}