We are here to help you with any of your needs.
You can get the software on the following link: https://billing.1-stream.com/whmcs/
You can open a ticket here: https://billing.1-stream.com/whmcs/submitticket.php
Installation guide: https://billing.1-stream.com/whmcs/index.php/knowledgebase/2/Installation.html
Yes, you can get the software on the following link: https://billing.1-stream.com/whmcs/index.php/store/streaming-platform/software-1-stream-core-platform-5-days-trail-account
For security reasons currently we don't offer demo website.