Sorting order items by SKU in Woocommerce

Question

I am trying to order the products by sku within an order in an email in Woocommerce.

I have not had any luck with the following code

Answer 1

In addition to @LoicTheAztec I've added the following check in the code:

if ($product instanceof WC_Product) {
                    $item_skus[$product->get_sku()] = $items_id;
                }

This prevents an error on the front-end customer orders page.

add_filter( 'woocommerce_order_get_items', 'filter_order_get_items_by_sku', 10, 3 );
function filter_order_get_items_by_sku( $items, $order, $types ) {
    if( count($items) > 1 ) {
        $item_skus = $sorted_items = array();

        // Loop through order line items
        foreach( $items as $items_id => $item ){
            // Check items type: for versions before Woocommerce 3.3
            if( $item->is_type('line_item') ){
                $product = $item->get_product(); // Get the product Object
                
                if ($product instanceof WC_Product) {
                    $item_skus[$product->get_sku()] = $items_id;
                }
            }
        }

        // Only for line items when our sku array is not empty
        if( ! empty($item_skus) ) {
            // Sorting in ASC order based on SKUs;
            ksort($item_skus); // or use krsort() for DESC order

            // Loop through sorted $item_skus array
            foreach( $item_skus as $sku => $item_id ){
                // Set items in the correct order
                $sorted_items[$item_id] = $items[$item_id];
            }
            $items = $sorted_items;
        }
    }
    return $items;
}