use Symfony\Component\Form\AbstractType; use Symfony\Component\Form\FormBuilderInterface; use Symfony\Component\Form\Extension\Core\Type\TextType; class UserType extends AbstractType { public function buildForm(FormBuilderInterface $builder, array $options) { $builder ->add('username', TextType::class) ->add('email', TextType::class) ; } public function configureOptions(OptionsResolver $resolver) { $resolver->setDefaults([ 'data_class' => User::class, ]); } public function getBlockPrefix() { return 'user'; } }In this example, the UserType class implements the FormInterface and defines two form fields - 'username' and 'email'. It also sets the default options for the form and returns the prefix used for the form's name as 'user'. The FormInterface is part of the Symfony\Component\Form package library.