Example of parameters for register_sidebar() function in WordPress

register_sidebar-parameters.php

<?php
  register_sidebar( [
    'name'          => esc_html__( 'Sidebar', 'themename' ),
    'id'            => 'main-sidebar',
    'description'   => esc_html__( 'Add widgets here.', 'themename' ),
    'before_widget' => '<section class="widget">',
    'class'         => 'custom-widget-area',
    'after_widget'  => '</section>',
    'before_title'  => '<h2 class="widget-title">',
    'after_title'   => '</h2>',
  ] );

?>