class ExampleType extends AbstractType
{
    public function getParent(): string
    {
        return Type\ChoiceType::class;
    }

    public function configureOptions(OptionsResolver $resolver): void
    {
        $resolver->setDefaults([
            'data_class' => MyEntity::class,
            'choice_value' => fn (\Stringable|string|null $entity): string => (string) $entity,
        ]);
    }
}