Stripe

1. Get your Secret Key from dashboard.stripe.com/apikeys (use a test key first) and paste it below. 2. Go to dashboard.stripe.com/webhooks, click "Add endpoint", and paste the webhook URL shown above. 3. Select at least the checkout.session.completed event (and any others you need), then save. 4. Stripe shows a "Signing secret" (starting with whsec_) for that endpoint — copy it into "Webhook Secret" below.