Seeking help regarding the simple text message example

[PawBud]

Hey, So I am using the following code :-

@Override
    public void send(Notification notification, User user, Event event, Position position) {
        String token = "Access Token";
        String phone_number = "Phone number without the '+'";
        String phone_number_id = "phone number id";

        WhatsappApiFactory factory = WhatsappApiFactory.newInstance(token);
        WhatsappBusinessCloudApi whatsappBusinessCloudApi = factory.newBusinessCloudApi();
        var message = MessageBuilder.builder()//
                .setTo(phone_number)//
                .buildTextMessage(new TextMessage()//
                        .setBody(Formatter.bold("Hello world!") + "\nSome code here: \n" + Formatter.code("hello world code here"))//
                        .setPreviewUrl(false));

        whatsappBusinessCloudApi.sendMessage(phone_number_id, message);
    } 

When this particular function is called, nothing happens, and there is no error whatsoever in the terminal or the browser console as this function is triggered when a button is clicked on a website. Is there any way you can help me?

[PawBud]

Update: It worked, I just had to write back to the test phone number as suggested here