JavaScriptでスライドショーの画像が表示されません。

サンプルのコードを参考にしたのですが、上手くスライドショーが実装できません。それ以前に、画像が表示されません。よろしくお願いいたします。

var slideIndex = 1;
    showSlides(slideIndex);

//ボタンのコントロール
function plusSlides(n){
  showSlides(slideIndex += n);
}

//画像のコントロール
function showSlides(n){
  var i;
  var slides = document.getElementsByClassName("mySlides");
  var slides = document.getElementsByClassName("dot");

  if (n>slides.length){
    slideIndex = 1;
  }

  if (n<1){
    slideIndex = slides.length
  }

  for (i=0; i<slides.length; i++){
    slides[i].style.display = "none";
  }

  for (i=0; i<DOMStringList.length; i++){
    dots[i].className = dots[i],className.replace("avtive", "")
  }

  slides[slideIndex-1].style.display = "block";

  dots[slideIndex-1].className += "active";

}

{
  box-sizing: border-box;
}

body {
  color: white;
  text-align: center;
  font-size: 0.8rem;
  background: url('file:///Users/owner/Downloads/Canva%20-%20Photo%20of%20Flowers%20on%20Bucket.jpg') fixed;
  background-size: cover;
}

.header {
  padding: 170px 30 px 80px;
  height: 100vh;
}

.bg-mask {
  background: rgba(255, 255, 255, 0.5);
  width: 60%;
  margin: 0 auto;
  padding-top: 10;
}

.site-title-sub {
  margin: 200px 30px 0px 30px;
  padding-top: 10px;
  letter-spacing: 1px;
  font-size: 2rem;
  color: #330000;
  font-family: "DM Serif Display", cursive;
}

.site-title {
  margin: 50px;
  font-size: 8rem;
  color: #330000;
  font-family: "DM Serif Display", cursive;
}

.site-description {
  margin-bottom: 50px;
  color: #FF0461;
  font-size: 3rem;
  font-family: "DM Serif Display", cursive;
}

/*検索フォーム*/
.form1 {
  position: relative;
  max-width: 300px;
  margin-bottom: 20px;
}

.sbox1 {
  height: 50px;
  padding: 0 10px;
  position: absolute;
  left: 0;
  top: 0;
  border-radius: 25px;
  outline: 0;
  background: #eee;
}

.subtn1 {
  height: 50px;
  width: 50px;
  position: absolute;
  left: 250px;
  top: 0;
  background:#7fbfff;
  color: #fff;
  border: none;
  border-radius: 0 25px 25px 0;
}

.sbtn1 .fa-search {
  font-size: 20px;
  position: absolute;
  top: 30%;
  left: 30%;
}

.sbtn1 :hover {
  color: #888;
}

/*コンテンツ*/
.contents {
  height: 100vh;
  margin: 0 50px;
  background-color: white;
  position: relative;
}

.heading1 {
  display: inline-block;
  margin: 30px 0 15px;
  padding-bottom: 15px;
  letter-spacing: 2px;
  color: #330000;
  font-size: 4rem;
  font-family: "DM Serif Display", cursive;
}

/*スライドショー*/
.slideshow-container {
  max-width: 1000px;
  position: relative;
  margin: auto;
}

.mySlides {
  display: none;
}

/*ボタン*/
.prev, .next {
  cursor: pointer;
  position: absolute;
  top: 50%;
  width: auto;
  margin-top: -22px;
  padding: 16px;
  color: #330000;
  font-weight: bold;
  font-size: 18px;
  transition: 0.6s ease;
  border-radius: 0 3px 3px 0;
  user-select: none;
}

/*次へボタンを右の位置にする*/
.next {
  right: 0;
  border-radius: 3px 0 0 3px;
}

/*ボタンを透かせる*/
.prev:hover, .next:hover {
  background-color: rgba(0, 0, 0, 0.8)
}

/*番号*/
.numbertext {
  color: #330000;
  font-size: 12px;
  padding: 8px 12px;
  position: absolute;
  top: 0;
}

.dot {
  cursor: pointer;
  height: 15px;
  width: 15px;
  margin: 0 2px;
  background-color: #bbb;
  border-radius: 50%;
  display: inline-block;
  transition: background-color 0.6s ease;
}

.active, .dot:hover {
  background-color: #717171;
}

/*フェイディングアニメーション*/
.fade {
  -webkit-animation-name: fade;
  -webkit-animation-duration: 1.5s;
  animation-name: fade;
  animation-duration: 1.5s;
}

@-webkit-keyframes fade {
  from {opacity: .4}
  to {opacity: 1}
}

@keyframes fade {
  from {opacity: .4}
  to {opacity: 1}
}

/*コンタクト*/
.footer {
  height: 100vh;
  padding: 80px 0 150px;
}

.heading2 {
  display: inline-block;
  margin: 30px 0 15px;
  padding-bottom: 15px;
  letter-spacing: 2px;
  font-size: 4rem;
  font-family: "DM Serif Display", cursive;
}

.contact-form {
  width: 50%;
  margin: 50px auto 0;
}

.contact-form input[type=text], .contact-form textarea {
  display: block;
  width: 100%;
  margin-bottom: 10px;
  padding: 15px;
  outline: none;
  border: 1px solid rgba(255, 255, 255, 0.8);
  border-radius: 0;
  color: #333;
}

.contact-form textarea {
  height: 150px;
}

.contact-form input[type=submit] {
  display: block;
  width: 200px;
  margin: 40px auto 0;
  padding: 15px;
  border: 1px solid rgba(255,255, 255);
  border-radius: 5px;
  color: #333;
  cursor: pointer;
}

<!DOCTYPE html>
<hrml>
<head>
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta charset="UTF-8">
  <title>LoF</title>

  <mata name="description" content="">
  <meta name="author" content="">
  <meta name="viewport" content="width=device-width, initial-scale=1">

  <link rel="stylesheet" type="text/css" href="kadai.css">
  <link type="text/html" href="https://fonts.google.com/specimen/DM+Serif+Display">
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/Swiper/4.5.0/css/swiper.min.css"/>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/Swiper/4.5.0/js/swiper.min.js"></script>
  <script type="text/javascript" src="kadai.js"></script>
  <!--[if lt IR 9]>
  <script src="//cdnjs.cloudflare.com/ajax/libs/html5shiv/3.7.2/html5shiv.min.js"></script>
  <script src="//cdnjs.cloudflare.com/ajax/libs/respond.js/1.4.2/respond.min.js"></script>
  <![endif]-->
    
</script>

</head>

<body>
  <header class="header">
    <div class="bg-mask">
      <p class="site-title-sub">----- Language of Flowers -----</p>
      <h1 class="site-title">LoF</h1>
      <p class="site-description">Find your happiness.</p>

      <form id="form1" action="#" method="get"> 
      <input id="sbox1" id="search" name="search" type="text" placeholder="Flower name"/>
      <button id="sbtn1" type="submit"><i class="fas fa-search"></i>
      </button>
      </form>
    </div>
  </header> 

  <div class="contents">

    <h2 class="heading1">Seasonal Flowers</h2>
    <div class="slideshow-container">
      <div class="mySlides fade">
        <div class="numbertext">1/3</div>
        <img src="file:///Users/owner/Downloads/Canva%20-%20null.jpg" width="600" height="400">
        <div class="text">Hibiscus</div>
      </div>

      <div class="mySlides fade">
        <div class="numbertext">2/3</div>
        <img src="file:///Users/owner/Downloads/Canva%20-%20Close-up%20Photo%20Of%20Sunflower.jpg" width="600" height="400">
        <div class="text">Sunflower</div>
      </div>

      <div class="mySlides fade">
        <div class="numbertext">3/3</div>
        <img src="file:///Users/owner/Downloads/Canva%20-%20null%20(1).jpg" width="600" height="400">
        <div class="content">Cosmos</div>
      </div>

      <a class="prev" onclick="plusSlides(-1)">&#10094;</a>
      <a class="next" onclick="plusSlides(1)">&#10095;</a>
    </div>
    <br>

    <div style="text-align: center">
      <span class="dot" onclick="currentSlide(1)"></span>
      <span class="dot" onclick="currentSlide(2)"></span>
      <span class="dot" onclick="currentSlide(3)"></span>
    </div>

  </div>

  <div class="footer">
    <h2 class="heading2">Contact</h2>
      <form class="contact-form">
        <input type="text" name="name" placeholder="NAME">
        <textarea name="message" placeholder="MESSAGE"></textarea>
        <input type="submit" value="SEND">
      </form>
    </div>
  </div>
</body>
</hrml>