How can I delete documents 3 months older?

[Mary2022 (Mary)]

@carly.richmond

POST /my-index/_delete_by_query
{
  "query": {
    "range": {
      "timestamp": {    
        "lte": "2023-004-01T00:00:00", 
      }
    }
  }
}

Sorry if I am a little lost but does ILM only apply for new documents?

I use the reindex API to reindex only the results/documents obtained from the API to a new index. Ones that id done I will delete the index.