I wish it could be that easy. But security is a must these days, and with any software, as you add features it grows more complex. So eventually it is a bit harder to install and configure, especially given all the different server environments. So the Xibo developers did identify that installation was becoming complex, so they decided on using Docker containers, and manual install as an option. Docker containers and wrapping ones head around that is unfortunately a-whole-nother thing in itself. But I would suggest the Docker route after going down it.
They should be available. I am not sure where they are available for download, but maybe try Googling, Xibo CMS and the version number you want.
You might also consider host xibo as a solution.