#include <ESP32Servo.h>

#define servoPin 4
int btnPins[4] = {5,18,19,21};

Servo myservo;

void setup() {
  myservo.attach(servoPin, 500, 2400);

  for(int i = 0; i <= 3; i ++){
    pinMode(btnPins[i], INPUT_PULLUP);
  }
}

void loop() {
  if(!digitalRead(btnPins[0])){
    myservo.write(0);
  }else if(!digitalRead(btnPins[1])){
    myservo.write(60);
  }else if(!digitalRead(btnPins[2])){
    myservo.write(120);
  }else if(!digitalRead(btnPins[3])){
    myservo.write(180);
  }
  delay(10);
}