LARAVEL INERTIA - TRANSLATIONS

composer require mariuzzo/laravel-js-localization

config/app.php - Providers:
  Mariuzzo\LaravelJsLocalization\LaravelJsLocalizationServiceProvider::class,
  
php artisan lang:js resources/js/Lang/translations.js --no-lib --quiet

// RUN COMMAND IN THE COMPILED
npm i webpack-shell-plugin-next

// LANG
npm install @eli5/vue-lang-js

IN webpack.config.js : 

module.exports = {
  ...,
  plugins : [
        new WebpackShellPluginNext({
            onBuildStart : {
                scripts : ['php artisan lang:js resources/js/Lang/translations.js --no-lib --quiet'], 
            }
        })
    ],
}
// end webpack.config.js

Add File: 
resources/js/Lang/index.js

require('lang.js');
import VueLang.     from '@eli5/vue-lang-js'
import translations from './translations.js';

Vue.use(VueLang, {
  messages: translations, // Provide locale file
  locale:   'en', // Set locale
  fallback: 'en' // Set fallback lacale
});


// app.js

require('Lang/')