install qemu ubuntu 20.04

C++
sudo apt install qemu qemu-utils qemu-kvm virt-manager libvirt-daemon-system libvirt-clients bridge-utils


Then you will have to add an user to the following using Uses and Group software

kvm, libvirt, dnsmasq, libvirt-qemu


Installation of Uses and Group software


sudo apt install gnome-system-tools



Source

Also in C++: