How to set up iptables rules to log traffic from and to the router?

Question

iptables

It, actually, addition to my last question
DMZ is configured. In theory, all traffic goes to it. Therefore, I'm not sure that it will be possible to see outgoing traffic.
Actually, iptables is configured on the server in the DMZ zone.
Right now, but it doesn't work:

-A INPUT -d 123.123.123.123 -j LOG --log-prefix "iptables: [in] "
-A OUTPUT -s 123.123.123.123 -j LOG --log-prefix "iptables: [out] "

123.123.123.123 - external ip of the router