View not Found web/app/index.html

Yii 2.0 Installation and Setup
1

It installs a project that is already exposed to the public. I have a few problems, many url works, but on which ones I have an error

View not Found – yii\base\ViewNotFoundException

The view file does not exist: /home/project_dir/web/app/index.html

I fire applications from apache2 locally

2

You need to tell us more.

Is app your AppController and no action was specified in the url?

Read about two methods to render static pages:
https://www.yiiframework.com/doc/guide/2.0/en/structure-views#rendering-static-pages

3

An example: let’s use ViewAction with about.php renamed to about.html and using pretty url format.

 class SiteController extends Controller
 {
     public function actions()
     {
         return [
             'page' => [
                 'class' => 'yii\web\ViewAction',
             ],
         ];
     }
 }

Add the view (about.html) to
views/site/pages/

Add a rule to urlManager component section in the config (web.php)
e.g
'static/<view:[\w\.]+>' => 'site/page',

Display the static page using this url
<server><the_project>/web/static/about.html

With the web folder as DocumentRoot
<server>/static/about.html