Create a user using a single PHP file I have tried every possible ways to create a user account using only a single PHP file without writing a module. I want to create a portal in which visitors can subscribe or register themselves and do something after they logged in. I have also a mobile application (Android and iOS) in which my app users can register (subscribe) and use the app in their mobile phone. Both the web application and the mobile application use the same API to create a Drupal 8 user. Is there anyone who help me out to achieve this?
If you want a single php file you can use a drush shell script:

#!/usr/bin/env drush

use Drupal\user\Entity\User;

    $user = User::create(['name' =&gt; 'testuser', 'status' =&gt; TRUE]);
    $user-&gt;save();


For more information see https://github.com/drush-ops/drush/blob/master/docs/shellscripts.md

A better approach might be to use REST, see https://www.drupal.org/node/2754633