Reading data received from Nextion on Serial Monitor

Other Hardware Displays
20

The TJC is a Nextion but made in the Chinese Nextion factory and is in "Chinese" language but programs exactly like a US Nextion except that the overlay is not in English but the internal code is in English and Exactly like Nextion.For all intents and purposes it is a Nextion except that the HMI files are not interchangable.

https://unofficialnextion.com/t/nextion-and-tjc-whats-the-difference/20

I have found this simple code which works for me in sending both text & values(with minor code modification) from the Nextion to the Arduino and at the same time Serial Display the received text or number received to the Serial Monitor.

int aaa = 0;
int bbb = 0;

void setup() {
  Serial.begin(9600);
  Serial.println ("   GIDDAY  ");
}



void loop() {

  if (Serial.available())
  {
    String datA = "";
    delay(30);
    while (Serial.available()) 
      datA += char(Serial.read());

      //Serial.println(datA);
      //sendData(datA);//
      aaa = datA.toInt();
      if (aaa > 0) {
        Serial.println(aaa);
        bbb = (aaa * 12);
        Serial.println (bbb);
        Serial.println ("      RETURN TO NEXTION");
  // ,,,,,,,,,,,,,,,,,,,,, Here I am trying to change the colour of the Nextion Button from White to Red,,,,,,,,,,,,,,,,,,,,,,
  //,,,,,,,,**I think my problem is here with The Serial.Print not actually going out to the Nextion. I think I somwhow nedd to**
**  //,,,,,,,,create another Serial output but I am not sure how to do it.**
  Serial.print("b0.pco=63488");
  Serial.write(0xff);
  Serial.write(0xff);
  Serial.write(0xff);
      }
    }

  }

The Code works just fine Nextion to Arduino but not the other way around.
I think i need another Serial port for Arduino to Nextion.
Can you help?