How to convert a nested json object into an excel table using the xlsx npm library?

I've got a nested json object. For the sake of simplicity:

data = {'key1': 1, 'key2': 2, 'key3': {'nestedKey1': 3, 'nestedKey2': 4}}

A real object is bigger but the point is that it's a nested one. Values may be strings, numbers or other objects. Now I need to get an excel table that (for this specific json would look like this):

|----------------------------------------
| key1 | key2 |           key3          |
|      |      |--------------------------
|      |      | nestedKey1 | nestedKey2 |
|----------------------------------------
|  1   |  2   |     3      |      4     |
|----------------------------------------

In order to do this I tried using the xlsx library. I import the lib as follows:

import { WorkSheet, WorkBook, utils, writeFile } from 'xlsx';

Inside my method I define the object:

let myObj = {'key1': 1, 'key2': 2, 'key3': {'nestedKey1': 3, 'nestedKey2': 4}}

then I create a worksheet and workbook:

const workSheet: WorkSheet = utils.json_to_sheet([myObj]);
const workBook: WorkBook = utils.book_new();
utils.book_append_sheet(workBook, workSheet, 'object_to_save');

and finally write it to a file:

writeFile(workBook, 'Tests.xlsx');

But quite expectedly it doesn't process the nested object the way I would like it to. I can't figure out what I should do to get the desired result.

from How to convert a nested json object into an excel table using the xlsx npm library?