Just install these packages and restart the VM:
1.) Enable guest-utils on the host side:
sudo apt install virtualbox-guest-utils virtualbox-guest-x11
2.) Enable guest editions on the VMside
This must be done for each VM that you want to have the guest additons for accelerated GPU performance and for drag and drop/clipboard sharing
First insert the Guest Addtions CD image........
The best way is as below in .htaccess using modrewrite, any request that is not SSL will be redirected to https://domain.com and the exact same URL
RewriteCond %{SERVER_PORT} 80
RewriteRule ^(.*)$ https://domain.com/$1 [R=301,L]........