Outbound nat maps

Im doing a nat map but I want the server go out only for the public ip that I assigned, when I forced outbound use the interface ip.

This can be achieved. Please find the screenshot below.

but if I want like example the unifi, and not the others?

The outbound policy determines which WAN link gets used and the outbound NAT map determines which IP address gets used.

After a fews test, I find that first you need to make the outbound nat map, save and apply, then make the outbound policy, save and apply, because when I made the two rules then save and apply the outbound policy take the interface ip.

Thank you for the update, good to hear you got this working.