Bluetooth thermal printer

[Bobbik]

I've got a device, (battery charger) which has a rs232 port and a printer , which prints summary after each charge cycle. I 'm trying to replace this printer with BT one, so I connected it like this:
charger->rs232 ttl adapter-> esp32 _> bluetooth serial printer.
I know serial parameters of old printer, printer is connected via Bluetooth corectly, however it prints some chinese symbols (looks like a pattern) . I use :

  // Forward all data from the physical serial to the Bluetooth serial
  while (Serial2.available()) {
    SerialBT.write(Serial2.read());

From Esp to printer i can print correctly
When i change it to SerialBT.print, it prints a string of digits. I can't determine if old printer was in other printing mode, or code page or something

[Bobbik]

I couldn't decipher how a logo was send to a printer, so instead of that, i decided to set start sequence of redirect data to serialBT. now it is printed without a logo.

//btprinter1.8a
#include "BluetoothSerial.h"

const char startSequence[] = "Device";
const int sequenceLength = sizeof(startSequence) - 1; // Subtract 1 to exclude the null terminator
bool sequenceMatched = false;
BluetoothSerial SerialBT;
const int LED_PIN = LED_BUILTIN;
const int BUTTON_PIN = 26;
bool buttonState = false;
unsigned long buttonPressTime = 0;
unsigned long lastButtonPressTime = 0;
const unsigned long DEBOUNCE = 50;
bool restartRequested = false;
uint8_t address1[6] = {0x66, 0x22, 0x45, 0xEB, 0x8B, 0x75};
bool connected = false;
#define RXD2 16
#define TXD2 17

void setup() {
  Serial.begin(115200);
  Serial2.begin(115200, SERIAL_8N1, RXD2, TXD2);

  SerialBT.begin("ESP32test", true);
  pinMode(LED_PIN, OUTPUT);
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  attachInterrupt(digitalPinToInterrupt(BUTTON_PIN), restartButtonPressed, FALLING);
  SerialBT.setPin("0000");

  Serial.println("The device successfully started!");

  connected = SerialBT.connect(address1);

  if (connected) {
    digitalWrite(LED_PIN, HIGH);
    Serial.println("Connected successfully!");
    SerialBT.print("\n");
    SerialBT.print("Drukarka podlaczona \n");
    SerialBT.print("przez Bluetooth!\n");
    SerialBT.print("\n");

    SerialBT.write(0x1B);
    SerialBT.print('@');
    Serial.write(0x1B);
    Serial.write(0x1C);
    Serial.write(0x2E);
  } else {
    while (!SerialBT.connected(5000)) {
      Serial.println("Failed to connect. Make sure remote device is available and in range, then restart app.");
      for (int i = 0; i <= 2; i++) {
        digitalWrite(LED_PIN, HIGH);
        delay(400);
        digitalWrite(LED_PIN, LOW);
        delay(200);
      }
    }
  }
}

void loop() {
  if (Serial2.available()) {
    char c = Serial2.read();

    if (!sequenceMatched && c == startSequence[0]) {
      //SerialBT.print('D');
      sequenceMatched = true;
    }

    if (sequenceMatched) {
      SerialBT.print(c);
    }
     // Check if restart button has been pressed
    if (restartRequested) {
      restartRequested = false;
      delay(500);
      Serial.println("Restarting...");
      ESP.restart();
    }
  }
}

void restartButtonPressed() {
  buttonPressTime = millis();

  if (buttonPressTime - lastButtonPressTime > DEBOUNCE) {
    Serial.println("Restarting...");
    delay(500);
    ESP.restart();
  }
}

Next goal is to find out how to print own bitmap to raw bluetooth printer