How to fix a messed-up frontpage?

Get a solution for the issue, need to change in apache2.conf file after that it will works,

old code in /etc/apache2/apache2.conf is

<Directory /var/www/>
        Options Indexes FollowSymLinks
        AllowOverride None
        Require all granted
</Directory>

changed into

 <Directory /var/www/>
            Options Indexes FollowSymLinks
            AllowOverride All
            Require all granted
    </Directory>

after that, In order for Apache to understand rewrite rules, we first need to activate mod_rewrite. It’s already installed, but it’s disabled on a default Apache installation. Use the a2enmod command to enable the module:

$ sudo a2enmod rewrite

This will activate the module or alert you that the module is already enabled. To put these changes into effect, restart Apache.

$ sudo systemctl restart apache2

it works.