Link the rest of your Stripe payments

// Where your server creates the PaymentIntent (the Payment Element, Elements).
const visitorId = req.cookies['_tally_vid'];
const paymentIntent = await stripe.paymentIntents.create({
  amount: 4900,
  currency: 'usd',
  automatic_payment_methods: { enabled: true },
  metadata: visitorId ? { 'tally_visitor_id': visitorId } : {},
});

// A subscription your server creates: its invoices carry its metadata.
const visitorId = req.cookies['_tally_vid'];
const subscription = await stripe.subscriptions.create({
  customer: customerId,
  items: [{ price: 'price_123' }],
  metadata: visitorId ? { 'tally_visitor_id': visitorId } : {},
});

// When you create the customer (or later, with stripe.customers.update).
const visitorId = req.cookies['_tally_vid'];
const customer = await stripe.customers.create({
  email: user.email,
  metadata: visitorId ? { 'tally_visitor_id': visitorId } : {},
});

// Once the customer is signed in (or on your success page), with the email they pay with.
// It is hashed when it arrives; only the hash is kept.
window.tally = window.tally || function () { (tally.q = tally.q || []).push(arguments); };
tally('identify', { email: user.email });