REQUIRED PDO library with pdo_sqlite extension is not available.

1) First Check whether the sqlite module is present in php module by executing the following command.
php -m | grep pdo
php -m | grep sqlite

If you didn't get any output,that says the module absence

2) Now,check the sqlite3 module in apt repository.

root@user-linuxhelp:~# apt-cache search php | grep sqlite3

php-sqlite3 - SQLite3 module for PHP [default]

php7.2-sqlite3 - SQLite3 module for PHP

3) Install the module based on your php version (In my case its 7.2)
apt install php7.2-sqlite3 -y

4) Now check the sqlite3 module in php by executing the following command
php -m | grep sqlite3

Now,it will show you the module.

Thus,resolved the error