Codeigniter Version 4.1.7 Rest API Routing Post method not working - codeigniter-4

Question

I am using Codeigniter Version 4.1.7.
Where I am implementing Rest API.
In the routes the GET method works,however Post method is not working.
I am testing this using POSTMAN.
URL : http://localhost/myproject/api/add-user
Following is the header
Accept: application/json
Content-Type: application/json
Authorization: Basic xxxxxxxxxxx=
Please check the code below for reference.
Routes.php
$routes->setDefaultNamespace('App\Controllers');
$routes->setDefaultController('Home');
$routes->setDefaultMethod('index');
$routes->setTranslateURIDashes(false);
$routes->set404Override();
$routes->setAutoRoute(false);
/*
* --------------------------------------------------------------------
* Route Definitions
* --------------------------------------------------------------------
*/
// We get a performance increase by specifying the default
// route since we don't have to scan directories.
//$routes->get('/', 'Home::index');
$routes->group("api", ["namespace" => "App\Controllers\Api", "filter" => "basicauth"] , function($routes){
$routes->get("list-users", "ApiController::index");
$routes->post("add-user", "ApiController::create");
});
ApiController.php
app\Controllers\Api\ApiController.php
<?php
namespace App\Controllers\Api;
use CodeIgniter\RESTful\ResourceController;
use App\Models\UsersModel;
class ApiController extends ResourceController
{
/**
* Return an array of resource objects, themselves in array format
*
* #return mixed
*/
public function index()
{
//
$users = new UsersModel();
$response = [
'status' => 200,
"error" => false,
'messages' => 'User list API',
'data' => $users->findAll()
];
return $this->respondCreated($response);
}
/**
* Create a new resource object, from "posted" parameters
*
* #return mixed
*/
public function create()
{
//
$rules = [
'first_name' => 'required|min_length[3]|max_length[20]',
'last_name' => 'required|min_length[3]|max_length[20]',
'email' => 'required|min_length[6]|max_length[50]|valid_email|is_unique[users.email]',
'password' => 'required|min_length[8]|max_length[255]',
'password_confirm' => 'matches[password]',
];
...
...
...
return $this->respondCreated($response);
}
}
Any help would be appreciated.