Use this tool to create custom code for Sidebars with register_sidebar() function. Fill out the form, update the code, copy the code to your theme.
// Register Sidebar
function custom_sidebar() {
$args = array(
'id' => 'unique_id',
'name' => __( 'Sidebar Name', 'text_domain' ),
'description' => __( 'Sidebar Description', 'text_domain' ),
'before_title' => '<h2 class="widgettitle">',
'after_title' => '</h2>',
'before_widget' => '<li id="%1$s" class="widget %2$s">',
'after_widget' => '</li>',
);
register_sidebar( $args );
}
// Hook into the 'widgets_init' action
add_action( 'widgets_init', 'custom_sidebar' );