birthdaywish_firework-1.0.0/birthday_wish_firework.module

<?php

use \Drupal\user\Entity\User;

/**
 * Implements hook_page_attachments().
 */
function birthday_wish_firework_page_attachments(array &$attachments) {
// Load the configuration data for 'birthday_wish_firework.settings'.
  $myConfigPageData = \Drupal::configFactory()->getEditable('birthday_wish_firework.settings');
  $enFirework = $myConfigPageData->get('enable_fireworks');

// Load the currently logged-in user.
  $current_user = \Drupal::currentUser();
  $uid = $current_user->id();
  $user = User::load($uid);

// Check if the user entity has the "field_birthdate" field.
  if($user->hasField('field_birthdate')){
    $bdate = $user->get('field_birthdate')->value;
    $attachments['#attached']['drupalSettings']['bdate'] = $bdate;
  }
// Attach the 'fireworksjs' library and set drupalSettings.
  $attachments['#attached']['drupalSettings']['firework'] = $enFirework;
  $attachments['#attached']['library'][] = 'birthday_wish_firework/fireworksjs';
}