How to put a body in get request in c# using Flurl?

Question

I'm trying to put a body in a get request using Flurl on c#. I need to make a code that makes a get request as this curl :

curl -X GET "localhost:9200/my-index-000001/_search?from=40&size=20&pretty" -H 'Content-Type: application/json' -d'
{
  "query": {
    "term": {
      "user.id": "kimchy"
    }
  }
}
'

Hope you can help me :)