How do I pass cart items to a checkout page?

// Add-to-cart route
app.post('/add-to-cart', function (req, res) {
    const { productId, quantity } = req.body;
    console.log('Adding to cart - Product ID:', productId, 'Quantity:', quantity);

    const productDetails = getProductDetailsFromMenu(productId);
    console.log('Product Details:', productDetails);

    if (productDetails) {
        req.session.cart = req.session.cart || [];
        console.log('Existing Cart:', req.session.cart);

        const existingItem = req.session.cart.find(item => item.productId === productId);

        if (existingItem) {
            existingItem.quantity += quantity;
        } else {
            req.session.cart.push({
                productId: productId,
                name: productDetails.name,
                basePrice: productDetails.basePrice,
                price: productDetails.basePrice * quantity,
                quantity: quantity,
                image: productDetails.image,
            });
        }

        console.log('Updated Cart:', req.session.cart);

        // Redirect to the homepage or menu page
        res.redirect('/menu');
    } else {
        res.status(404).send('Product not found');
    }
});

<div class="col-md-12 col-lg-12">
                            <div class="odr-box">
                                <div class="title-left">
                                    <h3>Shopping cart</h3>
                                </div>
                                <div class="rounded p-2 bg-light">
                                    <% if (listCarts && listCarts.length > 0) { %>
                                        <% listCarts.forEach(item => { %>
                                            <div class="media mb-2 border-bottom">
                                                <div class="media-body">
                                                    <a href="detail.html"><%= item.name %></a>
                                                    <div class="small text-muted">
                                                        Price: $<%= item.basePrice.toLocaleString() %> 
                                                        | Qty: <%= item.quantity %> 
                                                        | Subtotal: $<%= item.price.toLocaleString() %>
                                                    </div>
                                                </div>
                                            </div>
                                        <% }); %>
                                    <% } else { %>
                                        <p>No items in the cart</p>
                                    <% } %>
                                </div>
                            </div>
                        </div>

const cartData = localStorage.getItem('cartData');

        // Parse the cartData from JSON
        const listCarts = JSON.parse(decodeURIComponent(cartData));

        // Now, you can use the listCarts array to display the products on the checkout page
        console.log(listCarts);