With ipv6 wan interface its not possible to reach an ipv4 (ipv6 is not possible for this specific device) device over the internet. We need an translatoon from ipv6 -> ipv4. business application rules (dnat, waf) does not support mixed ipv4/6. only ipv6 for an ipv6 rule and vice versa.
Deepak Kumar commented
It must be support to nat66, Nat64