I'm trying to associate name in metadata with payment session and then access in webhook handler. How would I do that?

My code:

const session = await stripe.checkout.sessions.create({
    line_items: [
      {
        price: <priceid>,
        quantity: 1,
      },
    ],
    metadata: {
      nick: `${req.params.nick}`,
    },
    mode: "payment",
    success_url: `${process.env.DOMAIN}/success`,
    cancel_url: `${process.env.DOMAIN}/bany`,
  })

Webhook handler:

router.post(
  "/webhook",
  express.json({ type: "application/json" }),
  (request, response) => {
    const event = request.body

    // Handle the event
    switch (event.type) {
      case "checkout.session.completed":
        const data = <metadata from checkout session>
        console.log(data)
        break
      default:
        console.log(`Unhandled event type ${event.type}`)
    }

    response.json({ received: true })
  }
)