CODE EXAMPLE FOR HTML

Bootstrap 4 Search Box

<div class="input-group mb-3">
  <input type="text" class="form-control" placeholder="Search" aria-label="Search" aria-describedby="basic-addon2">
  <div class="input-group-append">
    <span class="input-group-text" id="basic-addon2">Search/span>
  </div>
</div>