Bug report #213365 (https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=213365) reported NTP doesn't use tcp, but udp port 123.
Additional research shows this is correct, from these two sources:
https://forums.freebsd.org/threads/30423/
https://forums.freebsd.org/threads/49826/
Created minor update based off these sources to update the command to use udp 123 instead of tcp 37.