Here is my “normal” config file and just “gets the task done”.

Here’s my Updated File

<IfModule mod_ssl.c>
  <VirtualHost *:443>
    ServerAdmin admin@domain.co.uk

    ServerName www.domain.co.uk
    ServerAlias domain.co.uk

    DocumentRoot /var/www/html/domain

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

      # Redirect non-www to www
      RewriteEngine On

      RewriteCond %{HTTP_HOST} !^www\. [NC]
      RewriteRule ^(.*)$ https://www.%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
    </Directory>

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

    Include /etc/letsencrypt/options-ssl-apache.conf
    SSLCertificateFile /etc/letsencrypt/live/domain.co.uk/fullchain.pem
    SSLCertificateKeyFile /etc/letsencrypt/live/domain.co.uk/privkey.pem
  </VirtualHost>
</IfModule>

Where I have got the “Redirect non-www to www are the few lines where I have tried to make the changes done.