Need help with not being able to send data through bluetooth module

Hello! I'm using an HC-05 with the rx pin connected to d4 and tx to d5 of an Arduino nano. I'm pretty new to Arduino and wanted to test whether I'm able to send data through bluetooth module. I'm using an app called 'Arduino bluetooth text to speech' to recieve the data and convert it to speed, however, I'm not receiving any data. My code is as follows (I'm sorry I have no idea how to format it on this website).
#include <SoftwareSerial.h>
SoftwareSerial mySerial(4, 5); // RX, TX
void setup()
{
mySerial.begin(9600);
}

void loop()
{
if(Serial.available()){
mySerial.println("HELLO WORLD!");
delay(3000);
}
}

I feel the problem might be with my circuit connections since I hear bluetooth module's rx and tx pins need 3.3V instead of 5V. But it's hard to pinpoint what exactly went wrong, maybe my module is faulty, could I have your advise?

I'm using an HC-05 with the rx pin connected to d4 and tx to d5 of an Arduino nano.

SoftwareSerial mySerial(4, 5); // RX, TX

You need to be cross connected. RX module > TX Arduino(pin5) and TX module > RX Arduino(pin4).

It's best to use a voltage divider on the Arduino Tx > Module Rx so that 5v is dropped to 3.3.

image

Thank you! I'll try that out