const session = await stripe.checkout.sessions.create({ line_items: [ { price_data: { currency: 'usd', product_data: { name: 'T-shirt', }, unit_amount: 2000, }, quantity: 1, }, ], mode: 'payment', ui_mode: 'custom', return_url: '{{RETURN_URL}}', billing_address_collection: 'required', shipping_address_collection: { allowed_countries: ['US'], }, });