How to integrate payments into your App with Stripe?

If you build an app that requires you to take payments (credit card, debit card, etc.) and want to integrate Stripe payments into your app, setup your account first at Stripe.

Add Stripe checkout and subscriptions to my app.

Requirements:
– Backend: Create an API route `/api/checkout` that initializes a Stripe Checkout session for a <$20/month subscription>.
– Use Stripe's official SDK with environment variables for keys.
– Frontend: Add a `Subscribe` button that calls the API and redirects to Stripe checkout.
– Include webhook handler for successful payments that updates Supabase `users` table with `is_pro` flag.
– Error handling and confirmation page included.
– Output: production-ready backend (TypeScript) + frontend button component, responsive, Inter font with –6 letter spacing.