Elasticsearch : Root mapping definition has unsupported parameter

Mapping types are deprecated. Refer to this documentation to know more about the removal of mapping types.

Indices created in Elasticsearch 6.0.0 or later may only contain a single mapping type. Indices created in 5.x with multiple mapping types will continue to function as before in Elasticsearch 6.x. Types will be deprecated in APIs in Elasticsearch 7.0.0, and completely removed in 8.0.0.

{
  "settings": {
    "analysis": {
      "analyzer": {
        "trigrams": {
          "tokenizer": "trigram_tokenizer",
          "filter": [
            "lowercase"
          ]
        }
      },
      "tokenizer": {
        "trigram_tokenizer": {
          "type": "ngram",
          "min_ngram": 3,
          "max_ngram": 3,
          "token_chars": []
        }
      }
    }
  },
  "mappings": {            // note this
    "properties": {
      "correct": {
        "type": "text",
        "analyzer": "trigrams"
      }
    }
  }
}

If your JSON document is like this:

{
  "true_name": {
    "correct": "mapping types deprecated"
  }
}

Then index mapping will be -

{
  "settings": {
    "analysis": {
      "analyzer": {
        "trigrams": {
          "tokenizer": "trigram_tokenizer",
          "filter": [
            "lowercase"
          ]
        }
      },
      "tokenizer": {
        "trigram_tokenizer": {
          "type": "ngram",
          "min_ngram": 3,
          "max_ngram": 3,
          "token_chars": []
        }
      }
    }
  },
  "mappings": {
    "properties": {              // note this
      "true_name": {
        "properties": {
          "correct": {
            "type": "text",
            "analyzer": "trigrams"
          }
        }
      }
    }
  }
}