How do I use Node.JS to run a web application? – Blancer.com Tutorials and projects

I am learning to code and I created an application that can write a simple Human Resources letter to test how to run my Javascript code on a server, using Node. The application works on my desktop, though when using the server on local host 3000, there is no functionality to my application.

My server.js code is as follows:

const express = require("express");
const bodyParser = require("body-parser");

const app = express();

app.use(express.static("Public"));

app.use(bodyParser.urlencoded({extended: true}));

//Route 1
app.get("/test", function(req, res){
res.sendFile(__dirname + "/test.html");
});

app.get("/test", function(req, res){

var submitButton = document.querySelector(".submit");
var statement = document.querySelector(".statement");

submitButton.addEventListener("click", ()=>{
    var nameInput = document.querySelector(".name-input-field").value;
    var letterType = document.querySelector("#letterType").value;


    var textTemplate = `Dear employee, 

    I am writing this letter to you in regards to the outcome of the recent disciplinary 
    meeting that we held. 
    
    replace paragraph
    
    If you have any queries regarding the content of this letter please do not hesitate 
    to contact me.` 
    
  
    var fittedText = textTemplate.replace(/b(employee)b/ig, nameInput)


    if(letterType == "Letter of Concern"){
    fittedText = fittedText.replace(/b(replace paragraph)b/ig, `On this particular 
    occasion I have decided not to proceed with formal disciplinary action. However, 
    this letter is to be treated as confirmation that I have discussed my concerns with 
    you and that you are expected to make every effort to address the shortcomings that 
    have been identified.
  This letter is not intended to be a formal warning and does not form part of the 
  company's disciplinary procedure, however, it will be kept in your personnel file and 
  thus takes the form of what I consider to be a reasonable written management 
  instruction.`)
  }
  if(letterType == "Written Warning"){
  fittedText = fittedText.replace(/b(replace paragraph)b/ig, `At the hearing you gave 
  no satisfactory explanation for your actions. Having carefully reviewed the 
  circumstances, I have decided that a written warning is the appropriate sanction. This 
  written warning will be placed on your personnel file but will be disregarded for 
  disciplinary purposes after six months, provided your conduct improves to a 
  satisfactory level.`)
  }
  if(letterType == "Final Written Warning"){
  fittedText = fittedText.replace(/b(replace paragraph)b/ig, `Having carefully 
  reviewed the circumstances, including the severity of the offence, I have decided that 
  a first and final written warning is the appropriate sanction.
  This first and final written warning will be placed on your personnel file but will be 
  disregarded for disciplinary purposes after twelve months, provided your 
  conduct/performance improves to a satisfactory level.`)
  }
  if(letterType == "Dismissal"){
  fittedText = fittedText.replace(/b(replace paragraph)b/ig, `Having carefully 
  considered all the evidenced presented at the disciplinary hearing, I have decided to 
  terminate your contract with immediate effect.`)
  }
  
    statement.innerText = fittedText

  });

  res.send(statement.innerText);

  });

  app.listen(3000, function(){
  console.log("Server started on port 3000");
  });

And my HTML is as follows:

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<!-- <link rel="stylesheet" href="css/styles.css">-->
</head>
<body>

<div class="test-container">
<h1>Human Resources Letter</h1>
<form> 
  <label>Employee's Name:</label>
  <input class="name-input-field" type="text"></input>
  <br>
  </form>
<br>
<form> 
  <label for="letter">Letter type?</label>  
  <select name="letter" id="letterType">
      <option disabled hidden selected>Select</option>
      <option value="Letter of Concern">Letter of Concern</option>
      <option value="Written Warning">Written Warning</option>
      <option value="Final Written Warning">Final Written Warning</option>
      <option value="Dismissal">Dismissal</option>
  </select>  
  </form>
  <br>
  <button class="submit">Submit</button>
  <br>
  </div>
  <h3 class="statement"></h3>
  <p class="statement"></p>
  <!--<script src="test.js"></script>-->
  </body>
  </html>