How to install v3 on Ubuntu 20.04?

Hello. Could you help, please: i can’t install V3 on Ubuntu 20.04. At first i’ve tried this
sudo bash -c "$(wget -O - https://raw.githubusercontent.com/bluecherrydvr/bluecherry-installer-scripts/master/web_install/install)"
and received:
Currently we only support Ubuntu 18.04 (Bionic) and Debian 10 (Buster) for unstable testing
Then i’ve tried this:
sudo bash -c “$(wget -O - http://dl.bluecherrydvr.com/scripts/install-unstable)”
and received
if: “#!/bin/bash: No such file or directory
Then i’ve downloaded this script, made it executable and run it:
sudo ./install-unstable
And received the same message:
Currently we only support Ubuntu 18.04 (Bionic) and Debian 10 (Buster) for unstable testing

I’ve done it this way:

wget -q https://dl.bluecherrydvr.com/key/bluecherry.asc -O- | apt-key add -
wget --output-document=/etc/apt/sources.list.d/bluecherry-focal.list http://unstable.bluecherrydvr.com/sources.list.d/bluecherry-focal.list
apt -y update
apt -y install bluecherry