JavaScript Snake Game Reset Button – Blancer.com Tutorials and projects

I am making a javascript snake game for my computer science class. It is due on Friday and I need help. I need to create a reset button but I’m not sure how to. Can someone help? Code is posted below.
*This is the index.html
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        body{
            margin: 0px;
            padding: 0px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
        }
        canvas{
            box-shadow: black 20px 10px 50px;
        }
    </style>    
</head>

<body>
    <h1>Snake</h1>
    
    <canvas id="game" width="400" height="400"/>
    <script src="index.js"></script>
    
</body>
</html>


This is the index.js
const canvas = document.getElementById("game");
const ctx = canvas.getContext("2d");

class SnakePart {
  constructor(x, y) {
    this.x = x;
    this.y = y;
  }
}


let speed = 7;

let tileCount = 20;
let tileSize = canvas.width / tileCount - 2;

let headX = 10;
let headY = 10;
const snakeParts = [];
let tailLength = 2;

let appleX = 5;
let appleY = 5;

let inputsXVelocity = 0;
let inputsYVelocity = 0;

let xVelocity = 0;
let yVelocity = 0;

let score = 0;

const gulpSound = new Audio("gulp.mp3");

function drawGame() {
  xVelocity = inputsXVelocity;
  yVelocity = inputsYVelocity;

  changeSnakePosition();
  let result = isGameOver();
  if (result) {
    return;
  }

  clearScreen();

  checkAppleCollision();
  drawApple();
  drawSnake();

  drawScore();

  if (score > 5) {
    speed = 9;
  }
  if (score > 10) {
    speed = 11;
  }

  setTimeout(drawGame, 1000 / speed);
}

function isGameOver() {
  let gameOver = false;

  if (yVelocity === 0 && xVelocity === 0) {
    return false;
  }

  if (headX < 0) {
    gameOver = true;
  } else if (headX === tileCount) {
    gameOver = true;
  } else if (headY < 0) {
    gameOver = true;
  } else if (headY === tileCount) {
    gameOver = true;
  }

  for (let i = 0; i < snakeParts.length; i++) {
    let part = snakeParts[i];
    if (part.x === headX && part.y === headY) {
      gameOver = true;
      break;
    }
  }

  if (gameOver) {
    ctx.fillStyle = "white";
    ctx.font = "50px Verdana";

    if (gameOver) {
      ctx.fillStyle = "white";
      ctx.font = "50px Verdana";

      var gradient = ctx.createLinearGradient(0, 0, canvas.width, 0);
      gradient.addColorStop("0", " magenta");
      gradient.addColorStop("0.5", "blue");
      gradient.addColorStop("1.0", "red");
      ctx.fillStyle = gradient;

      ctx.fillText("Game Over!", canvas.width / 6.5, canvas.height / 2);
    }

    ctx.fillText("Game Over!", canvas.width / 6.5, canvas.height / 2);
  }

  return gameOver;
}

function drawScore() {
  ctx.fillStyle = "white";
  ctx.font = "10px Verdana";
  ctx.fillText("Score " + score, canvas.width - 50, 10);
}

function clearScreen() {
  ctx.fillStyle = "black";
  ctx.fillRect(0, 0, canvas.width, canvas.height);
}

function drawSnake() {
  ctx.fillStyle = "green";
  for (let i = 0; i < snakeParts.length; i++) {
    let part = snakeParts[i];
    ctx.fillRect(part.x * tileCount, part.y * tileCount, tileSize, tileSize);
  }

  snakeParts.push(new SnakePart(headX, headY)); 
  while (snakeParts.length > tailLength) {
    snakeParts.shift(); 
  }

  ctx.fillStyle = "orange";
  ctx.fillRect(headX * tileCount, headY * tileCount, tileSize, tileSize);
}

function changeSnakePosition() {
  headX = headX + xVelocity;
  headY = headY + yVelocity;
}

function drawApple() {
  ctx.fillStyle = "red";
  ctx.fillRect(appleX * tileCount, appleY * tileCount, tileSize, tileSize);
}

function checkAppleCollision() {
  if (appleX === headX && appleY == headY) {
    appleX = Math.floor(Math.random() * tileCount);
    appleY = Math.floor(Math.random() * tileCount);
    tailLength++;
    score++;
    gulpSound.play();
  }
}



document.body.addEventListener("keydown", keyDown);

function keyDown(event) {

  if (event.keyCode == 38 || event.keyCode == 87) {
 
    if (inputsYVelocity == 1) return;
    inputsYVelocity = -1;
    inputsXVelocity = 0;
  }


  if (event.keyCode == 40 || event.keyCode == 83) {

    if (inputsYVelocity == -1) return;
    inputsYVelocity = 1;
    inputsXVelocity = 0;
  }


  if (event.keyCode == 37 || event.keyCode == 65) {

    if (inputsXVelocity == 1) return;
    inputsYVelocity = 0;
    inputsXVelocity = -1;
  }


  if (event.keyCode == 39 || event.keyCode == 68) {

    if (inputsXVelocity == -1) return;
    inputsYVelocity = 0;
    inputsXVelocity = 1;
  }
}

drawGame();
The game works otherwise, I just need a reset button! Can someone please reply with the right code and where to put it! Thanks so much.