http://ciisqbg45nggykdl6rjdrq3wc64csga4vkphu66qsi65mypeitqedoad.onion/pfsense
If you're using IPv6, add a mapping for the WAN Interface, with source set to fd00:20:20::/64 (or whatever IPv6 network you chose for the LAN interface earlier), and Translation set to WAN Address. Then add another mapping after that for the OPT1 Interface, with source set to fd00:20:20::/64 (or whatever IPv6 network you chose for the LAN interface earlier), and Translation set to OPT1 Address.