i have a problem using timer 1 fast pwm prescaler 64 tinkercad

Projects Programming
4 
volatile uint32_t ul_contador = 0;
#define pulsador 5

void setup()
{
  pinMode(pulsador, INPUT);
  DDRB |= (1 << DDB2);
  InitPWM1();
}

void loop() {

}

void InitPWM1() {
  cli();
  OCR1A = 2500; //64 Preescaler
  OCR1B = 250;
  TCCR1B |= (1 << WGM12) | (1 << WGM13);
  TCCR1A |= (1 << WGM10) | (1 << WGM11);
     
  //Timer 1 Preescaler 1
  TCCR1B &= ~(1 << CS12);
  TCCR1B |= (1 << CS11);
  TCCR1B |= (1 << CS10);
  TCCR1A |= (1 << COM1B1);
  TCCR1A &= ~ (1 << COM1B0);
  TIMSK1 |= (1 << OCIE1A);    
  sei();
}

ISR(TIMER1_COMPA_vect) {
  static byte step = 1;
  ul_contador++;
  if (ul_contador >= 400) {
    step++;
    OCR1B += 250;
    ul_contador = 0;
    if ( step >= 10 ) {
      step = 1;
      OCR1B = 250;
    }
    TCNT1 = 0;   
  }
}