Secondary menu

I am using the Twenty Twenty-one template in my WordPress site.

I am trying to add a code snippet in my site so it shows a secondary menu only when the user logs in the system. I already created a secondary empty menu. I am using the following code snippet but it would not work:

function add_login_logout_register_menu( $items, $args ) {
	if ( $args->theme_location != 'secondary-menu' ) {
		return $items;
	}
	if ( is_user_logged_in() ) {
		$current_user = wp_get_current_user();
		$items .= "Hola " . esc_html( $current_user->user_login ) . " | ";
		$items .= '<a href="' . wp_logout_url() . '">CERRAR SESIÓN</a>';
	} else {
		$items .= '<a href="/login">INICIAR SESIÓN</a>';
		$items .= '<a href="/registro">CREAR CUENTA</a>';
	}
	return $items;
}
add_filter( 'wp_nav_menu_items', 'add_login_logout_register_menu', 10, 2 );

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