After installing a minimal Ubuntu Bionic Beaver (18.04) distribution, open a terminal and type or copy/paste the following command
wget -q -O - https://install.rivendell-fr.org/bionic | sudo bash
...then press "Enter" key and wait for the process to complete. After that, you should be able to launch rdairplay and test with the test cart.
The current release version is Rivendell 3.6.4
The same applies to these distributions
wget -q -O - https://install.rivendell-fr.org/noble | sudo bash