Attribute revenue with Vercel v0

I need to add DataFast revenue attribution tracking to my Stripe payment integration. I don't know which Stripe method is currently implemented, so please analyze the existing code and implement the appropriate solution.

Here are the 4 possible implementations based on what's currently in the code:

METHOD 1 - If using Stripe Payment Links:
If you find Stripe Payment Links being used, tell me to follow this guide instead: https://datafa.st/docs/stripe-payment-links (this requires configuration in the Stripe dashboard, not code changes)

METHOD 2 - If using Stripe Checkout API (stripe.checkout.sessions.create):
Enhance the checkout session creation to include DataFast visitor tracking:
1. Read 'datafast_visitor_id' and 'datafast_session_id' cookies from the incoming request
2. Add these values to the checkout session metadata:
metadata: {
  datafast_visitor_id: cookieValue1,
  datafast_session_id: cookieValue2
}
See full documentation: https://datafa.st/docs/stripe-checkout-api

METHOD 3 - If using Stripe PaymentIntent API (stripe.paymentIntents.create):
Enhance PaymentIntent creation to include DataFast visitor tracking:
1. Read 'datafast_visitor_id' and 'datafast_session_id' cookies from the request
2. Add these values to the PaymentIntent metadata:
metadata: {
  datafast_visitor_id: cookieValue1,
  datafast_session_id: cookieValue2
}
See full documentation: https://datafa.st/docs/stripe-payment-intent-api

METHOD 4 - If using any other Stripe method or unsure:
Add client-side payment tracking on the success page:
window.datafast("payment", { email: customerEmail });
Replace 'customerEmail' with the actual customer email from the payment.
See full documentation: https://datafa.st/docs/stripe-other-methods

Please:
1. Examine the current Stripe payment implementation to determine which method is being used
2. Implement the appropriate solution above
3. Tell me which method you implemented