Fatal error: Uncaught Error: Class 'Drupal\Core\Form\FormBase' not found in /var/www/html/tmp/contrib/simple_oauth/src/Controller/Oauth2AuthorizeForm.php:20 Stack trace: #0 {main} thrown in /var/www/html/tmp/contrib/simple_oauth/src/Controller/Oauth2AuthorizeForm.php on line 20