If you need to load a specific form mode for the user's edit-form then you can do like below
Step 1: Create the services file e.g gym_misc.services.yml to register the routing event subscriber
services:
gym_misc.route_subscriber:
class: Drupal\gym_misc\Routing\RouteSubscriber
tags:
- { name: event_subscriber }
Step 2: Create the event subscriber class src/Routing/RouteSubscriber.php and modify the user edit routing to load your form mode. I am setting it to user.register form mode for edit form.
<?php
namespace Drupal\gym_misc\Routing;
use Drupal\Core\Routing\RouteSubscriberBase;
use Symfony\Component\Routing\RouteCollection;
/**
* Listens to the dynamic route events.
*/
class RouteSubscriber extends RouteSubscriberBase {
/**
* {@inheritdoc}
*/
protected function alterRoutes(RouteCollection $collection) {
if ($route = $collection->get("entity.user.edit_form")) {
$route->setDefault('_entity_form', 'user.register');
}
}
}