Register custom image transformers in CraftCMS

Plugin.php

<?php

use Craft;
use craft\base\Plugin;
use craft\elements\Asset;
use craft\events\GenerateTransformEvent;

use craft\events\RegisterComponentTypesEvent;
use craft\services\ImageTransforms;

use my\namespace\CustomTransformer;

use yii\base\Event;

class MyPlugin extends Plugin
{
    public function init(): void
    {
        parent::init();

        // Register the transformer(s) with Craft
        Event::on(
            ImageTransforms::class,
            ImageTransforms::EVENT_REGISTER_IMAGE_TRANSFORMERS,
            function (RegisterComponentTypesEvent $event) {
                $event->types[] = CustomTransformer::class;
            }
        );

        // Use the selected transformer
        Event::on(
            Asset::class,
            Asset::EVENT_BEFORE_GENERATE_TRANSFORM,
            function (GenerateTransformEvent $event) {
                $event->transform->setTransformer(CustomTransformer::class);
            }
        );

    }
}