A demo of this nature is not offered because there isn't much of interest that can be "visually" demonstrated.

You simply setup one or more billing packages in iPanel or ModernBill, and configure the disk space, bandwidth, and other stream limits for each package.  Then, when a client purchases a package through the billing system, a corresponding account is created in Centova Cast.  If the billing account is suspended (for non-payment or otherwise) or is cancelled, the client's stream is suspended or cancelled in Centova Cast as well.

Essentially the integration features just allow your billing system to automate the process of provisioning and deprovisioning streams in Centova Cast, so that you don't have to do it manually.  If you're familiar with how iPanel or ModernBill integrate with CPanel or Plesk, it's the exact same idea and the exact same interface in iPanel -- the only difference is that the accounts are created in Centova Cast instead of CPanel.