AVR Freaks

Hi everyone, I hope a lot in your help, I have a circuit with attiny85 that does on off with sleep, etc., I would like you to control a led driver in pwm but I don't know how to do it.

https://www.flashled.com.ua/imag...

#include <avr/sleep.h>
#include <avr/power.h>

const byte LED = 1;  // D1 / pin 2
const byte SWITCH = 2; // D2 / pin 6 / PCINT2
volatile byte last_sw_state = HIGH;
volatile byte led_state = LOW;
volatile long last_sw_change_millis = 0;
byte sw_state = HIGH;
long sw_read_millis = 0;

 // Interrupt Service Request. Executed when the state of the pin changes
 ISR(PCINT0_vect)
 {
 }
 
void setup()
{
  pinMode (LED, OUTPUT);
  pinMode (SWITCH, INPUT_PULLUP);

  cli(); // Disable interrupt
  // Pin change interrupt
  PCMSK  |= bit (PCINT2);  // D2 / pin 7
  GIFR   |= bit (PCIF);    // Clear any outstanding interrupts
  GIMSK  |= bit (PCIE);    // Enable pin change interrupts
  sei(); // Enable interrupt
}

void loop()
{
  sw_state = digitalRead(SWITCH); // or faster: (PINB >> PINB2) & 1
  sw_read_millis = millis();
  if (last_sw_state==HIGH && sw_state==LOW) { // Falling edge
      last_sw_change_millis = sw_read_millis;
  }
  if (last_sw_state==LOW && sw_state==LOW &&
      sw_read_millis-last_sw_change_millis>1000) {
    led_state = !led_state;    
    digitalWrite (LED, led_state);
    enter_sleep ();
  }
  last_sw_state = sw_state; 
}

void enter_sleep ()
{
  // Enter sleep
  set_sleep_mode(SLEEP_MODE_PWR_DOWN);
  ADCSRA = 0; // Turn off ADC
  power_all_disable (); // Power off ADC, Timer 0 and 1, serial interface
  sleep_enable();
  sleep_cpu();

 // …zzz

 // Wake up
  sleep_disable();
  power_all_enable(); // Power everything back on
}