How to create custom wordpress logout button(wp_logout_url) in wordpress?

custom wordpress logout button(wp_logout_url) in wordpress

<li class="menu-logout"><a href="<?php echo wp_logout_url(); ?>"><span><i class="fa fa-sign-out"></i></span>Logout</a></li>

Or

<li class="signOut"><?php wp_logout(); ?></li>

add_action( 'wp_logout', 'auto_redirect_external_after_logout');
function auto_redirect_external_after_logout(){
  wp_redirect( 'http://redirect-url' );
  exit();
}