frontend/controllers/TextController.php

<?php
namespace frontend\controllers;
use Yii;
use yii\web\Controller;
use common\models\Page;
use yii\web\HttpException;
class TextController extends Controller
{
    public function actionIndex()
    {
            if(!$modelText = Page::find()->where(['translit'=>$_GET['translit']])->one())
                    throw new HttpException(404, 'Данной странице не существует!');
            
            return $this->render('index', [
                    'text'=>$modelText,
            ]);
    }    
    
}