Arduino LCD via I2C (PCF8574AP)

Hi guys, I found the problem on HD44780 (16x2) display via I2C with a PCF8574AP.
when I uploaded the example sketch, there are a few problems. The first line is filled with black boxes.
I’m not able to print text on the display.

is there any solution ??

I use this code

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x38,16,2); // set the LCD address to 0x20 for a 16 chars and 2 line display

void setup()
lcd.init(); // initialize the lcd

// Print a message to the LCD.
lcd.print(“Hello, world!”);

void loop()

I use this schematic