Register new order status on WooCommerce

functions.php

/**
 * Register new status
 *
**/
add_action('init', function() {
    register_post_status('wc-producao', array(
        'label'                     => 'Em produção',
        'public'                    => true,
        'exclude_from_search'       => false,
        'show_in_admin_all_list'    => true,
        'show_in_admin_status_list' => true,
        'label_count'               => _n_noop('Em produção <span class="count">(%s)</span>', 'Em produção <span class="count">(%s)</span>')
    ));
});

// Add to list of WC Order statuses
add_filter('wc_order_statuses', function($order_statuses) {
    $new_order_statuses = array();
    foreach ($order_statuses as $key => $status) {
        $new_order_statuses[$key] = $status;
        if ('wc-processing' === $key) {
            $new_order_statuses['wc-producao'] = 'Em produção';
        }
    }
    return $new_order_statuses;
});