I would like to execute an example of Graph query in some example data to understand how it works, but when i execute, nothing is returned

Elastic Search
1

I'm trying to execute this example:

POST /transacoes/_bulk
{ "index": { "_id": "1" } }
{ "conta_origem": "A", "conta_destino": "B", "valor": 100 }
{ "index": { "_id": "2" } }
{ "conta_origem": "A", "conta_destino": "C", "valor": 150 }
{ "index": { "_id": "3" } }
{ "conta_origem": "B", "conta_destino": "C", "valor": 200 }
{ "index": { "_id": "4" } }
{ "conta_origem": "C", "conta_destino": "A", "valor": 50 }


POST /transacoes/_graph/explore
{
  "query": {
    "match_all": {}
  },
  "vertices": [
    {
      "field": "conta_origem.keyword"
    },
    {
      "field": "conta_destino.keyword"
    }
  ],
  "connections": {
    "vertices": [
      { "field": "conta_destino.keyword" }
    ]
  }
}

But when i execute the query, nothing is returned. Is there soming i'm doing wrong?