bootstrap 4 stop auto slide

$('.carousel').carousel({
  interval: false,
});

You just need to add one more attribute to your DIV tag which is 
 `data-interval="false"`
 So <!--Carousel Wrapper-->
 <div id="multi-item-example" class="carousel slide carousel-multi-item" data-ride="carousel" data-interval="false">

Note* : no need to touch JS!

<------------------ OR ---------------------->

$('.carousel').carousel({
  interval: false,
});