This is for 64 bit VirtualBox version: 6.1.18, Debian GNU/Linux 10 (buster)
(and non-systemd derivatives MX, Devuan, ...)
:To Install
<install_package_names>
virtualbox
virtualbox-ext-pack
virtualbox-guest-additions-iso
</install_package_names>
<postinstall>
gpasswd -M $(getent group users | cut -d: -f4) vboxusers
</postinstall>
:To Remove
<uninstall_package_names>
virtualbox
virtualbox-ext-pack
virtualbox-guest-additions-iso
</uninstall_package_names>