#include <ESP32Servo.h>

Servo servo;  // create servo object to control a servo

int potpin = 34;  // analog pin used to connect the potentiometer
int angle;    // variable to read the value from the analog pin
int analog_value; 
void setup() {
  servo.attach(13);  // attaches the servo on pin 9 to the servo object
}

void loop() {
   analog_value = analogRead(potpin);            // reads the value of the potentiometer (value between 0 and 1023)
   angle = map(analog_value, 0, 4095, 0, 180);     // scale it to use it with the servo (value between 0 and 180)
  servo.write(angle);     
  Serial.print("Analog: ");
  Serial.print(analog_value);
  Serial.print(angle);
  delay(100);             // sets the servo position according to the scaled value
                          // waits for the servo to get there
}