Stripe Checkout success URL not working

Add {CHECKOUT_SESSION_ID} to your success_url when you create the session, for example https://yoursite.com/success?session_id={CHECKOUT_SESSION_ID}. Type it exactly like that, braces included. Stripe swaps in the real ID when it sends the customer back. Don't put an ID there yourself. Stripe: modify the success URL

Make sure the URL points at your live site, not localhost or an old preview. Open it in a private window to see that the page loads without a login.

On the success page, read session_id from the URL and fetch that Checkout Session on your server to show the order. Your secret key stays on the server. Stripe: create the success page

Stripe says you can't rely on the success page alone, because customers aren't sure to visit it. Someone can pay and lose their connection before it loads. Stripe: webhooks are required for fulfillment

Listen for checkout.session.completed and, for slower payment methods, checkout.session.async_payment_succeeded. For subscriptions, Stripe says webhook fulfillment is required. Stripe: create a payment event handler

Run the same fulfill function from the webhook and from the success page. It may run more than once for one session, even at the same time, so record what you've done and skip repeats. Check payment_status before you give access. Stripe: create a fulfillment function

With a webhook endpoint and a success_url, Checkout waits up to 10 seconds for your server to answer checkout.session.completed before it redirects. A slow handler means a slow success page. Stripe: configure a landing page URL