Как добавить к слайдеру Bootstrap 4 кнопки для переключения?

@import "https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/css/bootstrap.min.css"; 
 
#carouselExampleIndicators { 
  width: 400px; 
} 
 
.carousel-indicators { 
  position: relative; 
  right: auto; 
  bottom: auto; 
  left: auto; 
  margin-right: 0; 
  margin-left: 0; 
  list-style: none; 
  background: red; 
} 
 
.carousel-indicators li { 
  width: 30px; 
  height: 30px; 
  text-indent: 0; 
  color: black; 
  font-size: 14px; 
  text-align: center; 
  cursor: pointer; 
}

<script src="https://code.jquery.com/jquery-3.2.1.slim.min.js"></script> 
 
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.3/umd/popper.min.js"></script> 
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0-beta.2/js/bootstrap.min.js"></script> 
<script> 
$('.carousel').carousel({ 
  interval: null 
}) 
</script> 
 
 
<!--Индикаторы--> 
<ol class="carousel-indicators"> 
  <li data-target="#carouselExampleIndicators" data-slide-to="0" class="active">1</li> 
  <li data-target="#carouselExampleIndicators" data-slide-to="1">2</li> 
  <li data-target="#carouselExampleIndicators" data-slide-to="2">3</li> 
</ol> 
 
<div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel"> 
 
  <div class="carousel-inner"> 
    <div class="carousel-item active"> 
      <img class="d-block w-100" src="https://avatars.mds.yandex.net/get-pdb/34158/57d750dc-6893-4a08-93c7-bcb2c0aec8b0/s800" alt="First slide"> 
    </div> 
    <div class="carousel-item"> 
      <img class="d-block w-100" src="https://1079638729.rsc.cdn77.org/pic/v2/gallery/preview/belki-zhivotnye-33658.jpg" alt="Second slide"> 
    </div> 
    <div class="carousel-item"> 
      <img class="d-block w-100" src="https://avatars.mds.yandex.net/get-pdb/34158/b4138e2d-0ebb-4c7c-9afc-5b20f705bab1/s800" alt="Third slide"> 
    </div> 
  </div> 
  <a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev"> 
    <span class="carousel-control-prev-icon" aria-hidden="true"></span> 
    <span class="sr-only">Previous</span> 
  </a> 
  <a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next"> 
    <span class="carousel-control-next-icon" aria-hidden="true"></span> 
    <span class="sr-only">Next</span> 
  </a> 
</div>