I am using the following code to show the total savings amount in checkout page:

add_action( 'woocommerce_review_order_after_order_total', 'show_total_discount_cart_checkout', 1000 );
function show_total_discount_cart_checkout() {
    $discount_total = 0; // Initializing

    // Loop through cart items
    foreach ( WC()->cart->get_cart() as $item ) {
        $product = $item['data'];

        if ( $product->is_on_sale() ) {
            $regular_args = array( 'price' => $product->get_regular_price() );

            if ( WC()->cart->display_prices_including_tax() ) {
                $active_price    = wc_get_price_including_tax( $product );
                $regular_price   = wc_get_price_including_tax( $product, $regular_args );
            } else {
                $active_price    = wc_get_price_excluding_tax( $product );
                $regular_price   = wc_get_price_excluding_tax( $product, $regular_args );
            }
            $discount_total += ( $regular_price - $active_price ) * $item['quantity'];
        }
    }

    if ( WC()->cart->display_prices_including_tax() ) {
        $discount_total += WC()->cart->get_discount_tax();
    }

    $discount_total += WC()->cart->get_discount_total();

    if ( $discount_total > 0 ) {
        $text = __("SÄÄSTÖSI", "woocommerce");

        printf( '<tr class="total-saved"><th>%s</th><td data-title="%s">-%s</td></tr>', $text, $text, wc_price($discount_total) );
    }
}

I would like also to show taht total savings amount in cart page and in the generated order. It seems to be the order-details.php temmplate responsible for customer orders.

How to show the total savings amount in cart page and in the generated order?