set nat66 destination rule 100 destination address '2001:db8::1'
set nat66 destination rule 100 inbound-interface name 'eth1'
set nat66 destination rule 100 translation address '2001:db8:2222::1'

set nat66 source rule 100 outbound-interface name 'eth2'
set nat66 source rule 100 source prefix '2001:db8:2222::/64'
set nat66 source rule 100 translation address 'masquerade'

vyos@r4:~$ show nat66 destination rules 
NAT is not configured
vyos@r4:~$ 

vyos@r4:~$ show nat66 source rules 
NAT is not configured
vyos@r4:~$ 

vyos@r4:~$ show version 
Version:          VyOS 1.5-rolling-202312040024
Release train:    current