Set or remove the account's webhook

Sets (or replaces) the target URL and the events you subscribe to. The response also includes the signing secret - save it right away, GET won't return it again later. An empty events: [] means subscribe to every event, not none - including ones added later. If you only want some events, list them. Conversely, an empty url: "" cancels the webhook - volai then sends nothing, and the response returns url: null. How to verify the signature is covered on the Webhooks.