improvements-2.x-dev/modules/improvements_paragraphs/improvements_paragraphs.install

<?php

use Drupal\Core\Field\BaseFieldDefinition;

/**
 * Implements hook_install().
 */
function improvements_paragraphs_install(): void {
  // Add "label" base field to paragraph entity
  $field = BaseFieldDefinition::create('string')
    ->setLabel(t('Label'));
  \Drupal::entityDefinitionUpdateManager()->installFieldStorageDefinition('label', 'paragraph', 'improvements_paragraphs', $field);

  // Add "Machine name" base field to paragraph entity
  $field = BaseFieldDefinition::create('string')
    ->setLabel(t('Machine name'))
    ->addConstraint('UniqueField');
  \Drupal::entityDefinitionUpdateManager()->installFieldStorageDefinition('machine_name', 'paragraph', 'improvements_paragraphs', $field);
  //\Drupal::database()->schema()->addUniqueKey('paragraphs_item_field_data', 'machine_name', ['machine_name']);
}