#include <ESP32Servo.h>

Servo myServo;

const int servoPin = 18;

void setup() {
  Serial.begin(115200);

  myServo.attach(servoPin);
  myServo.write(0);   // initial position

  Serial.println("Send 1 = Open, 0 = Close");
}

void loop() {
  if (Serial.available()) {
    char input = Serial.read();

    if (input == '1') {
      myServo.write(90);
      Serial.println("Servo OPEN");
    }

    if (input == '0') {
      myServo.write(0);
      Serial.println("Servo CLOSE");
    }
  }
}