Step 1 : Add the package cweagans/composer-patches
composer require cweagans/composer-patches

Doc : https://www.drupal.org/docs/drupal-apis/form-api/conditional-form-fields

States that can be applied to a form field element:

Add following packages to composer.json file next to drupal repository

Edit bashrc file (~/.bashrc)

PHP Class using StringTranslationTrait

StringTranslationTrait allow to get t() and formatPlural() methods
Example:
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\Core\StringTranslation\TranslationInterface;
class MyClass {