http://xmr4smsoncunkfgfjr6xmxl57afsmuu6rg2bwuysbgg4wdtoawamwxad.onion
Yes, use of Tor or VPNs are allowed and are recommended.
To use .onion for the CLI application, specify env variable MONERO_SMS_TOR=tor_socks_port Do you port numbers in or out? Numbers can be ported in for $1.49 or ported out for free.