Stripe to RunwayML Webhook Integration for my SAAS Website -- 2

I use Stripe Checkout links to sell monthly subscriptions and I run my AI video service through the Runway ML API. What I need is a small, secure webhook that listens to Stripe events, recognises the subscription tier a customer just paid for, and immediately calls the Runway ML REST endpoint to top up that customer’s usage. The flow should handle multiple subscription tiers (Basic, Pro, etc.), mapping each tier to a different credit amount in Runway ML. On a successful payment—checkout.session.completed or invoice.paid—the webhook must: • validate the Stripe signature • read the product / price ID to identify the tier • post the correct credit to Runway ML via its REST API • log the action to prevent double-crediting and for later auditing • return a 200 response so Stripe marks the event delivered THIS IS ALL I AM ASKING FOR DO NOT TRY TO UPSELL ON OTHER SERVICESES YOU OFFER SO YOU CAN CHARGE ME EXTRA, OR I WILL TERMINATE COMMUNICATION WITH YOU, THANK YOU. Please could do a test payment with a screen recording or screenshot to show me its completed.