Running ./register returns:
Could not get categories from Digium. Please check firewall and DNS settings.
You must be able to connect to register.digium.com via TCP port 443. If a
web proxy is required, run register --help for proxy usage instructions.
There’s no firewall rules blocking 443 traffic (confirmed via logs). Entering register.digium.com in a browser returns a certificate error. I’m able to ping the IP address it resolves to.