http://ciisqbg45nggykdl6rjdrq3wc64csga4vkphu66qsi65mypeitqedoad.onion/pfsense
Set Interface to LAN, Address Family to IPv4, Protocol to TCP/UDP, Destination to Any, the Destination Port range to DNS, and for Redirect target IP, select Address or Alias, and for Address type in 10.31.33.7 (or 10.31.33.8 if you don't want ad/tracker blocking). For Redirect target port, also set it to DNS.