Unable to extract a value from a JSON response to use as an enviroment variable in Postman - postman

Question

Pre Request:
//Create random number
let randomNum =
Math.floor((1 + Math.random()) * 0x10000)
.toString(16)
.substring(1);
//Set Random # as the Random ID
pm.environment.set("randomNum", randomNum);
Body:
{
"AccountNumber": "AA{{randomNum}}",
"Name": "AA {{randomNum}}",
"Reference": "AA 01",
"VatCodeId": 1,
"UserCreated": "James"
}
Response:
{
"Id": 18,
"AccountNumber": "AA7e40",
"Name": "AA 7e40",
"Reference": "AA 01",
"VatCodeId": 1,
"DateCreated": "2022-01-27T09:53:43.6734454+00:00",
"UserCreated": "James"
}
Note: The Id field is being created when a 200 response is being returned, this is unique to the DB and increments by 1 for every new account created.
I am trying to extract the Id and use that as a Enviroment variable so it can be chained (for deletion of accounts). The Test script is:
var accountUniqueId = JSON.parse(responseBody);
pm.environment.set("accountId", json.result.data.Id);
Though I have tried variations of it such as:
var accountUniqueId = pm.response.json();
pm.environment.set("accountId", jsonData.Id);
var accountUniqueId = pm.response.json();
pm.environment.set("accountId", jsonData.response.Id);
The response in the Test is showing as:
There was an error in evaluating the test script: ReferenceError: json is not defined
The Enviroment Variable is being created with a current value of:
[object Object].

Answer 1

This should do it:
let jsonData= pm.response.json();
pm.environment.set("accountId", jsonData.Id);