understrap/page-templates/left-sidebarpage.php

<?php
/**
 * Template Name: Left Sidebar Layout
 *
 * This template can be used to override the default template and sidebar setup
 *
 * @package understrap
 */

 get_header();
$container = get_theme_mod('understrap_container_type');
?>

<div class="wrapper" id="page-wrapper">


  <div class="wrapper" id="page-wrapper">

    <div class="<?php echo $container; ?>" id="content">

      <div class="row">

        <?php get_sidebar('left'); ?>

        <div class="<?php if ( is_active_sidebar( 'left-sidebar' ) ) : ?>col-md-8<?php else : ?>col-md-12<?php endif; ?> content-area" id="primary">

          <main class="site-main" id="main" role="main">

            <?php while ( have_posts() ) : the_post(); ?>

              <?php get_template_part( 'loop-templates/content', 'page' ); ?>

              <?php
              // If comments are open or we have at least one comment, load up the comment template
              if ( comments_open() || get_comments_number() ) :
                comments_template();
              endif;
              ?>

            <?php endwhile; // end of the loop. ?>

          </main><!-- #main -->

        </div><!-- #primary -->

      </div><!-- .row -->

    </div><!-- Container end -->

  </div><!-- Wrapper end -->

  <?php get_footer(); ?>