Bottom side of above link is :
- company do not display/mention his address, even in TOS
- Whois is using a proxy
They got verified identity by digicert for extented SSL certificate (green bar), but I think after being verified they passed to whois proxy
So there seem registered in Canada Vancouver, but can not find them using http://www.canadaregistry.ca
Offline payments does activate automatically as long as the invoice is marked as paid, and from what I remember 0$ invoices will be automatically marked as paid & after the service activated; just check your setting It may be that you have set to manually activate.
i have made some test , it appear your serverhosting blocking port 8006 .
just to note to every one, the core module didn't do any authentification verification , so it accept any data enter , my modulecheck the authentification , if the module can login to the proxmox server , it will be added .