curl --request POST \
  --url https://api.example.com/v1/projects/{project}:testWebhook \
  --header 'Content-Type: application/json' \
  --data '
{
  "project": "<string>",
  "webhook": {
    "type": "TYPE_UNSPECIFIED",
    "title": "<string>",
    "url": "<string>",
    "name": "<string>",
    "directMessage": true,
    "notificationTypes": [
      "TYPE_UNSPECIFIED"
    ]
  }
}
'

{
  "error": "<string>"
}