Registers a new webhook with the provided URL, description, agent(s), and subscribed event(s).
Schema name for multi-tenancy
URL to send webhook payloads to
"https://webhook.site/abcdef123456"
Description of the webhook purpose
"This is a test webhook to capture call start and end events."
List of agent IDs this webhook is associated with
List of events to subscribe to (e.g. call.started, call.ended)