13806: Invalid Client Notification URL

This error means the configured clientNotificationUrl is not a valid URL for Voice client call notifications. Twilio uses clientNotificationUrl to notify your application when a call routes to a Voice SDK client user, and the URL must contain a valid hostname, cannot include underscores, and only accepts POST.

• The configured clientNotificationUrl is malformed or otherwise not a valid URL.
• The URL hostname is invalid or includes underscores.
• The URL is not configured to use POST.

• Replace clientNotificationUrl with a valid URL that uses a valid hostname and does not include underscores.
• Configure the notification endpoint to accept POST requests.
• Verify your webhook handler responds appropriately to client call notifications. Twilio sends the request body as JSON, and the endpoint should return 200 OK when a matching client binding is found or 404 Not Found when it is not.

• TwiML Voice: <Client>
• Client Call Notification Webhook