backend

my_module.my_form_configuration_tab:
  route_name: my_module.my_form_configuration
  title: Configuration
  base_route: my_module.my_form_configuration

<?php

namespace Drupal\my_module\Plugin\EntityReferenceSelection;

use Drupal\Core\Entity\Plugin\EntityReferenceSelection\UserSelction;
use Drupal\Core\StringTranslation\TranslatableMarkup;

#[EntityReferenceSelection(
  id: "default:active_user",
  label: new TranslatableMarkup("User selection (only active users)"),
  entity_types: ["user"],
  group: "default",
  weight: 1
)]
class ActiveUserSelection extends UserSelection {

  /**
   * {@inheritdoc}
   */
  protected function buildEntityQuery($match = NULL, $match_operator = 'CONTAINS') {
    $query = parent::buildEntityQuery($match, $match_operator);
    $query->condition('status', 1);

    return $query;
  }

}

personal_data:
  '#type': html_tag
  '#tag': h3
  '#value': 'Personal data'

$form['nodes'] = [
    '#title' => $this->t('Select articles'),
    '#type' => 'entity_autocomplete',
    '#target_type' => 'node',
    '#tags' => TRUE,
    '#selection_handler' => 'default',
    '#selection_settings' => ['target_bundles' => ['article']],
    '#default_value' => $default_nodes,
];

$form['nodes'] = [
    '#title' => $this->t('Select articles'),
    '#type' => 'entity_autocomplete',
    '#target_type' => 'node',
    '#maxlength' => 1024,
    '#tags' => TRUE,
    '#selection_handler' => 'default',
    '#selection_settings' => ['target_bundles' => ['article']],
    '#default_value' => $default_nodes,
];

my_module.edit:
  options:
    # Enable the admin theme for this route.
    _admin_route: TRUE

<?php

namespace Drupal\scp_base\Routing;

use Drupal\Core\Routing\RouteSubscriberBase;
use Symfony\Component\Routing\RouteCollection;

class RouteSubscriber extends RouteSubscriberBase {

  /**
   * {@inheritdoc}
   */
  protected function alterRoutes(RouteCollection $collection) {
    // Make sure profile pages are not admin pages, in order to load the right
    // translation.
    if ($route = $collection->get('profile.user_page.single')) {
      $route->setOption('_admin_route', FALSE);
    }
  }

}