Kaltura install on ubuntu 20.04

Hello everyone,
First of all, please excuse my English level, I will try to be as clear as possible.
Here is the project: I work for a managed IT company and the goal is to offer VOD servers. The tool we have chosen is (for now) Kaltura.
During the installation I followed this link:

However, like for other people, this file does not exist at all in this directory.
I have the feeling that the documentation is no longer up-to-date, which means I cannot install this tool.
At the same time, I installed Kaltura via Docker but I realized (on Docker) that the last update was at least four years ago.

Could you please indicate a complete tutorial for this installation?
Or if you don’t have enough time, a few indications that could unblock me.

I also tried with this tutorial but I got the same errors as that person. (I tried with xenial, focal and debian repos)

When the installation will be complete, I am going to make and post a complete tuto in this forum.
So please, HELP ME ^^

I greatly appreciate anyone who takes the time to read this post and respond.
Thank you in advance.