I wrote this module for WHMCS at Feb 2016 and I tried to sell it via moduleland.com, But didn't sell at least one copy!
So i decided to publish it (which i worked on it about 2 months) open-source.
This is a PROXMOX VE module for WHMCS 6.x
You can see guides to install in manual folder. I did disable the license section and there's no need to obtain any license. So you can ignore license part in the manual.