请求Laravel空白页/index.php

When I go to:

http://example.com/index.php?lang=ru //example

I get a blank page, but why does laravel not redirect to the main page?

In index.php on directory laravel I changed:

if ($uri !== '/' && file_exists(__DIR__.'/public'.$uri)) {
  return false;
}

to

if ($uri !== '/' && file_exists(__DIR__.'/public'.$uri)) {
  echo $uri;
  return false;
}

And when I go to:

http://example.com/index.php?lang=ru

I get the message: /index.php.

How I can fix this solution?

The logs are empty. App debug is true.