$form = new \Symfony\Component\Form\FormBuilder(); $form->add('submit', \Symfony\Component\Form\Extension\Core\Type\SubmitType::class, ['label' => 'Save']);In this example, the addSubmit method is used to add a submit button to a form created using the Symfony\Component\Form library. The label for the button is set to 'Save'. This function is part of the Symfony\Component\Form\Extension\Core\Type\SubmitType package library.