Install Virtualbox Guest Additions in Kubuntu 20.4 Virtual Machine

Installing virtual box guest additions in a Kubuntu virtual machine with the default guest addition files may fail due to missing build files.

To make the default guest addition installer work, you may have to install build tools to rebuild the kernel module.
Instead, the easy and alternate approach is to download the appropriate packages directly from Ubuntu package repos.

Error Message

Install Guest Additions

# Update the repo
$ sudo apt update
$ sudo apt upgrade

# Install packages
$ sudo apt install virtualbox-guest-utils
$ sudo apt install virtualbox-guest-dkms