Add all order items SKU to order number in Woocommerce

i have this code that prefixes the product name into the order number through functions.php but i want to change it to add the SKU instead. Also it would be good, if the quantity of each SKU would be inserted as well.

Something like: 2xSKUA_1xSKUB_Ordernumber

Can someone point me in the right direction?

function filter_woocommerce_order_number( $this_get_id, $instance ) { 
    $order = new WC_Order( $this_get_id );
    $items = $order->get_items();
    foreach ( $items as $item ) {
        $product_name = preg_replace('/\s+/', '_', $item['name']);;
        break;
    }
    $new_id = $product_name.'_'.$this_get_id;

    return $new_id; 
}; 
add_filter( 'woocommerce_order_number', 'filter_woocommerce_order_number', 10, 2 );

To prefix order items (product) quantity with the SKU, to the order number, use the. following revisited code:

add_filter( 'woocommerce_order_number', 'filter_woocommerce_order_number', 10, 2 );
function filter_woocommerce_order_number( $order_number, $order ) {
    $prefix = array(); // Initializing

    // Loop through order items
    foreach ( $order->get_items() as $item ) {
        $product  = $item->get_product(); // Get the product object

        // Add the quantity with the sku to the array
        $prefix[] = $item->get_quantity() . 'X' . $product->get_sku(); 
    }
    // return everything merged in a string
    return implode('_', $prefix) . '_' . $order_number;
}

It should work as you expect.