hp/searchform.php

<form role="search" method="get" class="search-form" id="searchform" action="<?php echo home_url( '/' ); ?>">
  <div class="input-group mb-3">
    <input type="search" id="s" class="form-control search-field"
      placeholder="<?php echo esc_attr_x( 'Search', 'placeholder' ) ?>"
      value="<?php echo get_search_query() ?>" name="s"
      title="<?php echo esc_attr_x( 'Search for:', 'label' ) ?>" />
    <button class="btn btn-outline-light" type="submit"><i class="bi bi-search"></i></button>
  </div>
</form>