curl --location --request POST 'https://api.getmetal.io/v1/index' \
--header 'Content-Type: application/json' \
--header 'x-metal-api-key: <api-key>' \
--header 'x-metal-client-id: <client-id>' \
--data-raw '{
    "index": "index-id",
    "text": "text that will replace the existing document",
    "id": "id-to-update",
    "metadata": {
        "fieldA": "my custom value"
    }
}'

{
  "id": "id-to-update",
  "text": "text that will replace the existing document",
  "createdAt": "2023-03-17T17:21:13.163Z",
  "metadata": {
    "fieldA": "my custom value"
  }

}