Stripe webhook handler that verifies the signature correctly (Next.js App Router)

import Stripe from "stripe";
const stripe = new Stripe(process.env.STRIPE_SECRET_KEY!);

export async function POST(req: Request) {
  const body = await req.text();
  const sig = req.headers.get("stripe-signature")!;
  let event: Stripe.Event;
  try {
    event = stripe.webhooks.constructEvent(body, sig, process.env.STRIPE_WEBHOOK_SECRET!);
  } catch (e) {
    return new Response(`Bad signature: ${(e as Error).message}`, { status: 400 });
  }
  // handle event.type here; return 200 fast, do slow work in a queue
  return new Response("ok");
}