Thanks. Somehow code example №3 works correctly. I have used a library for timer and simplified code from the answer above.

#include <LiquidCrystal_I2C.h>
#include <millisDelay.h>       // Timer

#define button_pd 6

LiquidCrystal_I2C lcd(0x27, 16, 2);

int k = 0;
int cnt = 0;

uint8_t previous_state;  // previous state of the button

millisDelay d;

void setup() {
  pinMode(button_pd, INPUT_PULLUP);

  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(cnt);
}

void loop() {

    uint8_t state = digitalRead(button_pd);
    if (state == LOW)
        d.start(300);
    previous_state = state;
    if (d.justFinished()) {
        cnt = cnt + 1;
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print(cnt);
    }

}

Thanks. Somehow code example №3 works correctly. I have used a library for timer and simplified code from the answer above.

#include <LiquidCrystal_I2C.h>
#include <millisDelay.h>       // Timer

#define button_pd 6

LiquidCrystal_I2C lcd(0x27, 16, 2);

int k = 0;
int cnt = 0;

//uint8_t previous_state;  // previous state of the button

millisDelay d;

void setup() {
  pinMode(button_pd, INPUT_PULLUP);

  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(cnt);
}

void loop() {

    uint8_t state = digitalRead(button_pd);
    if (state == LOW)
        d.start(300);
    //previous_state = state;
    if (d.justFinished()) {
        cnt = cnt + 1;
        lcd.clear();
        lcd.setCursor(0, 0);
        lcd.print(cnt);
    }

}