Implements hook_form_FORM_ID_alter().
function paragraphs_library_form_paragraphs_type_form_alter(&$form, FormStateInterface $form_state) {
// Adds paragraph type grouping to the form.
/** @var \Drupal\paragraphs\ParagraphsTypeInterface $paragraph_type */
$paragraph_type = $form_state
->getFormObject()
->getEntity();
if ($paragraph_type
->id() != 'from_library') {
$form['allow_library_conversion'] = [
'#type' => 'checkbox',
'#title' => t('Allow promoting to library'),
'#default_value' => $paragraph_type
->getThirdPartySetting('paragraphs_library', 'allow_library_conversion', FALSE),
];
$form['#entity_builders'][] = 'paragraphs_library_form_paragraphs_type_form_builder';
}
}