Install UVDesk

Hello!
I am trying to install UVDesk , but I’m getting these errors.

My System:
Current Version: 2.3
Build: 4
Current Commit: 08cce2e80677e27b16572b9d80e131686f7f6d02
Latest Version: 2.3
Latest Build: 4
Latest Commit: 08cce2e80677e27b16572b9d80e131686f7f6d02

The Link for installing symfony isn’t working anymore.
https://cyberpersons.com/2017/12/14/using-composer-create-symfony-application-on-cyberpanel/

Thank you, Christoph