View file StuffPost/stuffpost/functions/function-sidebar.php

<?php

// sidebars
  add_action( 'widgets_init', 'weart_widgets_init' );
  function weart_widgets_init() {
    if ( function_exists('register_sidebar') ) {

      register_sidebar( array(
        'name' => esc_html__( 'Article Sidebar', 'stuffpost' ),
        'id' => 'sidebar-article',
        'description'   => esc_html__( 'Displays only in articles/pages.', 'stuffpost' ),
        'before_widget' => '<div id="%1$s" class="%2$s box mb-4 f-text l-black lh-1 c-black">',
        'after_widget'  => '</div>',
        'before_title'  => '<h4 class="text-uppercase mb-3 h5 pb-1 border-bottom brd-1 brd-width-bold">',
        'after_title'   => '</h4>',
      ) );

      register_sidebar( array(
        'name' => esc_html__( 'Footer Sidebar', 'stuffpost' ),
        'id' => 'sidebar-footer',
        'description'   => esc_html__( 'Displays only in the footer on all page.', 'stuffpost' ),
        'before_widget' => '<div id="%1$s" class="%2$s box col-lg-4 col-md-6 f-text l-meta lh-white c-meta border-right mb-4 mb-lg-0">',
        'after_widget'  => '</div>',
        'before_title'  => '<h4 class="text-uppercase mb-3 h5 pb-1 border-bottom c-white">',
        'after_title'   => '</h4>',
      ) );

      register_sidebar( array(
        'name' => esc_html__( 'WooCommerce Sidebar', 'stuffpost' ),
        'id' => 'sidebar-woocommerce',
        'description'   => esc_html__( 'Displays only in Shop pages.', 'stuffpost' ),
        'before_widget' => '<div id="%1$s" class="%2$s box mb-4 mt-2 f-text l-black lh-1 c-black">',
        'after_widget'  => '</div>',
        'before_title'  => '<h4 class="text-uppercase mb-3 h5 pb-1 border-bottom">',
        'after_title'   => '</h4>',
      ) );

    }
  }

// Widgets

  // latest posts
    require get_template_directory().'/functions/widget/widget-latest.php';

  // Category posts
    require get_template_directory().'/functions/widget/widget-category-posts.php';