Azure Key Vault is now a first party event publisher for Azure Event Grid. You can now trigger automation processes - through Azure Functions, WebHooks, or any other handlers - by subscribing to an event whenever there is a change on the status of a key, certificate or secret stored in Key Vault. Status changes include when one of these three types are about to expire, have expired, or when there is a new version available.
Azure Event Grid event schema for Azure Key Vault
Try it out with this tutorial
Learn more in docs