Does anyone have xBilling installed and working?

[Nigel]

I've never gotten Sabre to install properly.

Is there an install guide and/or repo? I tried manually installing the module, it doesn't show as 'Installed' but the files are there.
Two modules for that matter: sabre and sabre-module

There is also an error with the front-end: class 'sentora' not found in index.php line 17 (Changing class 'zpanelx' to 'sentora' in lib/functions.php fixes that.)

After years of being dormant, I'm in the process of trying to get Sabre module running on my test version.

I've fixed a couple of lines of code already and have the database installing properly.
The module itself was named incorrectly and that's why it wasn't installing.

Bare in mind I still can't code, so fudging my way through it.