If there is a ipv6 service online. That you want to reach from a v4 only client. You can set up a fixed 1:1 nat on your firewall where you define a fake internal ipv4 address -> destination NAT onto the public ipv6 address of the service. And SRC NAT64 embed your clients internal v4 into the source ipv6 for the return traffic. And provide a internal dns view A record pointing to the fake internal ip record. It would work, but does not scale very well. Since you would have to set this up for every ipv6 ip.

A better solution would be to use a dualstack SOCKS5 proxy with dns forwarding where the client would use the IPv6 of the proxy for the connection. But that does not use NAT tho.

The best solution is to deploy IPv6 ofcourse. ;)

You could still NAT between v6's though.