Your endpoint didn't accept the test event.
Avox sent a signed test event to your endpoint and didn't get a 2xx answer within 10 seconds. The result line next to the button says what happened (for example "Your endpoint answered 401").
Check the endpoint is deployed and reachable over https:// on port 443.
Verify the signature over the raw request body, using the current signing secret.
Answer 200 right away and do your own processing afterwards.
Send the test event again.
Still stuck? Send AVX-3101 to hello@theavoxai.com along with what you were doing when it happened.