#include <ESP32Servo.h>
Servo myservo;
int pos = 0;
int servoPin = 18;

void setup() 
{
 myservo.attach(servoPin, 500, 2400);
 ESP32PWM :: allocateTimer(0);
 ESP32PWM :: allocateTimer(1);
 ESP32PWM :: allocateTimer(2);
 ESP32PWM :: allocateTimer(3);
 ESP32PWM :: allocateTimer(50);
}

void loop() 
{
  for (pos = 0; pos<= 180; pos+=20)
  {
    myservo.write(pos);
    delay(1000);
  }
  for (pos = 180; pos>= 0; pos-=20)
  {
    myservo.write(pos);
    delay(1000);
  }
}