Controller or its method is not found: \\App\\Controllers\\Home::index

PHP Code:

$routes->group('api', function($routes){
    $routes->post('create-test', 'Api\v1\EmployeeController::create_test');
}); 


PHP Code:

namespace App\Controllers\Api\v1;
use CodeIgniter\RESTful\ResourceController;
class EmployeeController extends ResourceController
{  
    public function create_test(){
        return "okay";
    }

} 


Above produces below if accessed from URL: https://api.example.com/api/create-test and POSTMAN (verb POST)

    404 - File Not Found
    Create-test is not a valid controller name

My directory structure is;

 

Code:

  app/Controllers/Api/v1/EmployeeController.php

If I change the verb to GET, I get "okay".  Same with POSTMAN.

PHP Code:

$routes->group('api', function($routes){
    $routes->get('create-test', 'Api\v1\EmployeeController::create_test');
} 


I have had this problem many weeks so appreciate your help!