Error installing laravel 5.6 app on remote hosting

Hello, I am trying to install my laravel 5.6 app on remote hosting(digital ocean, Ubuntu 16.04.3)

I set DocumentRoot in /etc/apache2/sites-available to /public of my app

I added line in /etc/apache2/apache2.conf

ServerName localhost

and set all :

AllowOverride All

I made

a2enmod rewrite

and

sudo service apache2 restart

and

# sudo apache2ctl configtest
Syntax OK

Running in browser I got message

This page isn’t working
NNN.NN.NN.NNN is currently unable to handle this request.
HTTP ERROR 500

As I see error code my web hosting ok, that is some specific intermal error? But I want to see laravel error?

I run

sudo chmod -R 777 /var/www/html/box-booking/storage

log dir is empty:

and [email protected]:/var/www/html/box-booking/storage/logs# ls -la
total 12
drwxr-xr-x 2 root root 4096 Jul 22 06:13 .
drwxr-xr-x 6 root root 4096 Jul 22 06:13 ..
-rwxr-xr-x 1 root root   14 Jul 22 06:13 .gitignore

In my .env :

APP_NAME=Laravel
APP_ENV=local
APP_DEBUG=true
APP_LOG_LEVEL=debug
APP_URL=http://NNN.NN.

DB_CONNECTION=mysql
DB_HOST=127.0.0.1
DB_PORT=3306

In my /config/app.php I changed: 'env' => 'local', 'debug' => true,

But I stiil can not see any error...

Is it some cache of config? How to see the errors?

Thanks!