How to connect servo over I2c expander pin

Help me for how to call pin id over other lib i use myservo.attach(servoPin, 1000, 2000); <– servoPin is int how to call in other lib this my code i connect i2c pin P1

#include <ESP32Servo.h>
#include “PCF8575.h”

PCF8575 PCF(0x20);

Servo myservo; // create servo object to control a servo
// 16 servo objects can be created on the ESP32

int pos = 0; // variable to store the servo position
// Recommended PWM GPIO pins on the ESP32 include 2,4,12-19,21-23,25-27,32-33
// Possible PWM GPIO pins on the ESP32-S2: 0(used by on-board button),1-17,18(used by on-board LED),19-21,26,33-42
#if defined(ARDUINO_ESP32S2_DEV)
int servoPin = 17;
#else
int servoPin = 18;
#endif

void setup() {
// Allow allocation of all timers

	PCF.begin();

	ESP32PWM::allocateTimer(0);
	ESP32PWM::allocateTimer(1);
	ESP32PWM::allocateTimer(2);
	ESP32PWM::allocateTimer(3);
	myservo.setPeriodHertz(50); // standard 50 hz servo
	myservo.attach(servoPin, 1000, 2000); // attaches the servo on pin 18 to the servo object
// using default min/max of 1000us and 2000us
// different servos may require different min/max settings
// for an accurate 0 to 180 sweep
}

void loop() {

	for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees
// in steps of 1 degree
		myservo.write(pos); // tell servo to go to position in variable ‘pos’
		delay(15); // waits 15ms for the servo to reach the position
	}
	for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees
		myservo.write(pos); // tell servo to go to position in variable ‘pos’
		delay(15); // waits 15ms for the servo to reach the position
	}
}