How use systemd-nspawn with --network-veth and --port ( -n and -p)?

I run;

systemd-nspawn -n -p 80:80 -bD /path/to/httpd-container

In the container, httpd works. However, accessing from host, it dose not access. In addition, the below works without network options;

systemd-nspawn -bD /path/to/httpd-container

What do I need to use option -n, --network-veth and -p, --port?