curl --request GET \
  --url https://rt.tonapi.io/webhooks/{webhook_id}/account-tx/subscriptions \
  --header 'Authorization: Bearer <token>'

{
  "account_tx_subscriptions": [
    {
      "account_id": "<string>",
      "last_delivered_lt": 123,
      "failed_at": "<string>",
      "failed_lt": 123,
      "failed_attempts": 123
    }
  ]
}