delete.php

<?php
defined('APP_DIR') or define('APP_DIR', __DIR__ . '/../app/');
include_once(APP_DIR . 'model/User.php');
include_once(APP_DIR . 'include/http.php');

$data = User::authenticated();
if (!$data || $data->access != 'admin') {
    Http::redirect('index.php');
}

$username = Http::post_params()['username'];
$user = User::get($username);

if ($user) {
    $user->delete();
}

Http::redirect('admin.php');
?>