curl --request GET \
  --url https://console.vast.ai/api/v0/notification-types/ \
  --header 'Authorization: Bearer <token>'

{
  "success": true,
  "notification_types": [
    {
      "key": "client:low_credit",
      "slug": "low_credit",
      "topic": "billing",
      "category": "billing",
      "display_name": "Low balance notifications",
      "default_preferences": {
        "email": true,
        "webhooks": false
      },
      "mandatory_email": false
    }
  ]
}