Launch problems

[Grigorii-Voroshnin]

The installation of xterm and apache2 needs to be added to the documentation.
Ubuntu:

apt install xterm
apt install apache2

Also, before starting, check that port 53 is not busy.
Ubuntu:

sudo ss -lp "sport = :domain"

Very often it is occupied by systemd-resolved. He needs to be stopped.
Ubuntu:

sudo systemctl stop systemd-resolved
sudo systemctl disable systemd-resolved
sudo systemctl mask systemd-resolved

To undo what you did:
Ubuntu:

sudo systemctl unmask systemd-resolved
sudo systemctl enable systemd-resolved
sudo systemctl start systemd-resolved

In order for dnsmasq to start via xterm, it is advisable to stop it too.

systemctl stop dnsmasq.service