Restrict users to backorder specific products

WC User Role Backorder Allowed

add_action('init', 'add_backorder_allowed_role');
function add_backorder_allowed_role() {
    add_role(
        'backorder_allowed',
        __('Backorder Allowed', 'textdomain'),
        array(
            'read' => true, // This allows the user to read the content
            // Add other capabilities as needed
        )
    );
}


add_filter('woocommerce_product_is_in_stock', 'custom_backorder_permission', 10, 2);
function custom_backorder_permission($is_in_stock, $product) {
    // Define the product IDs that allow backorder
    $allowed_product_ids = array(123, 456, 789); // Replace with your product IDs

    if (in_array($product->get_id(), $allowed_product_ids) && $product->is_on_backorder(1)) {
        $current_user = wp_get_current_user();
        if (in_array('backorder_allowed', $current_user->roles)) {
            return true; // Allow backorder for users with the backorder_allowed role
        } else {
            return false; // Prevent backorder for all other users
        }
    }
    return $is_in_stock;
}

add_filter('woocommerce_variation_is_in_stock', 'custom_backorder_permission_for_variations', 10, 2);
function custom_backorder_permission_for_variations($is_in_stock, $variation) {
    // Define the product IDs that allow backorder
    $allowed_product_ids = array(123, 456, 789); // Replace with your product IDs

    if (in_array($variation->get_id(), $allowed_product_ids) && $variation->is_on_backorder(1)) {
        $current_user = wp_get_current_user();
        if (in_array('backorder_allowed', $current_user->roles)) {
            return true; // Allow backorder for users with the backorder_allowed role
        } else {
            return false; // Prevent backorder for all other users
        }
    }
    return $is_in_stock;
}