CI 4 Showing Blank Pages in ubuntu 20.04 LTS

Hi all
i did some pages in CI4 and hosted in Ubuntu 20.04 LTS desktop , but the pages are showing blank without any message.
i did many ways but the out put is same.

i tried the .htacess file as

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.)$ index.php/$1 [L]
RewriteCond %{HTTPS} !=on
RewriteRule ^(.)$ http://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]
</IfModule>


and enable rewrite_mod also .
please help if any solution for the same