update readme

etcd/readme.md

@@ -191,8 +191,11 @@ func main() {
 	}
 }
 ```
+## How to Dynamically specify ip and port
+
+To dynamically specify an IP and port, one should first set the environment variables `HERTZ_IP_TO_REGISTRY` and `HERTZ_PORT_TO_REGISTRY`. If these variables are not set, the system defaults to using the service's listening IP and port. Notably, if the service's listening IP is either not set or set to "::", the system will automatically retrieve and use the machine's IPV4 address.
 
 ## Compatibility
 
 Compatible with server (3.0.0 - 3.5.4)
-etcd-clientv3 [see](https://github.com/etcd-io/etcd/tree/main/client/v3)
+etcd-clientv3 [see](https://github.com/etcd-io/etcd/tree/main/client/v3)