<div class="swiper mySwiper">
    <div class="swiper-wrapper">
      <div class="swiper-slide"><img src="https://picsum.photos/id/13/2500/1667" alt=""></div>
      <div class="swiper-slide"><img src="https://picsum.photos/id/17/2500/1667" alt=""></div>
      <div class="swiper-slide"><img src="https://picsum.photos/id/16/2500/1667" alt=""></div>
      <div class="swiper-slide"><img src="https://picsum.photos/id/12/2500/1667" alt=""></div>
    </div>
    <div class="swiper-pagination"></div>
  </div>

html,
    body {
      position: relative;
      height: 100%;
    }

    body {
      background: #eee;
      font-family: Helvetica Neue, Helvetica, Arial, sans-serif;
      font-size: 14px;
      color: #000;
      margin: 0;
      padding: 0;
    }

    .swiper {
      width: 100%;
      height: 100%;
    }

    .swiper-slide {
      text-align: center;
      font-size: 18px;
      background: #fff;
      display: flex;
      justify-content: center;
      align-items: center;
    }

    .swiper-slide img {
      display: block;
      width: 100%;
      height: 100%;
      object-fit: cover;
    }


/* custom code */
.mySwiper .swiper-pagination {
  display: flex;
  align-items: end;
}
.mm-line-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: none;
  margin: 0 10px;
  cursor: pointer;
  opacity: .6;
}
.mm-line {
  width: 2px;
  height: 100px;
  background-color: #fff;
  border-radius: 0px;
  transition: .2s ease-in;
}
.mm-line-container.swiper-pagination-bullet-active {
  opacity: 1;
}
.mm-line-container.swiper-pagination-bullet-active .mm-line {
  height: 120px;
}
.mm-line-number {
  color: #fff;
}

var swiper = new Swiper(".mySwiper", {
  swipeHandler: '.swiper-wrapper',
  pagination: {
    el: ".swiper-pagination",
    clickable: true,
    bulletClass: 'mm-line-container',
    renderBullet: function (index, className) {
      return '<div class="mm-line-container ' + className + '"><span class="mm-line-number">' + (index + 1) + '</span><div class="mm-line"></div></div>';
    }
  }
});