I'm trying to integrate my software license key system into the ordering process so that the order confirmation email that customers get includes their license key. I have a webhook configured to call out to AWS Lambda which can process the new order information but I cannot figure out how to get shopify to actually DO anything with the response from that webhook call? Is that even possible? Ideally I want to return the new license key in the webhook response and then have that included in the confirmation email. Is there any way to do that? Right now I can't even find anything that would suggest that Shopify cares about the content of the webhook response beyond the HTTP status code being 200.
The webhooks delivery system needs to be generic across many different topics, apps, and delivery mechanisms, so it's a push-only system that only listens to the status code of the response to determine if the delivery of the webhook was successful or not. However, once your app receives information from a webhook, you can have it call the GraphQL / Rest APIs to perform other actions on the store. Perhaps something like https://shopify.dev/docs/admin-api/graphql/reference/orders/draftorderinvoicesend could be what you're looking for?