Create new schemas with openapi+json

Hello, I want to create new schemas on top of an existing api. I am trying to create them from openapi + json, but none of this is loaded in the azure api management, apparently this does not work.

Do you know if I am doing it the right way or is something missing to make it work?
Please

################## JSON ###################
{

"name": "string",

"type": "Microsoft.ApiManagement/service/apis/schemas",

"apiVersion": "2019-12-01",

"properties": {

  "contentType": "application/vnd.oai.openapi.components+json",

  "document": {

    "definitions": {

        "MyResponse": {

            "type": "object",

            "properties": {

                "requestId": {

                    "type": "string",

                    "description": "Request Code",

                    "example": "123456"

                },

                "responseGuessDate": {

                    "type": "string",

                    "description": "Date aprox",

                    "example": "30/07/2020"

                },

                "blockingId": {

                    "type": "string",

                    "description": "Primary Code",

                    "example": "456789"

                }

            }

        }

    }

  }

}

}