the machine a, i run a standalone pulsar, and can produce and consume message on machine a; but on machine b, how can i produce message?

**Is your feature request related to a problem? Please describe.**

the machine a, i run a standalone pulsar, and can produce and consume message on machine a;
but on machine b, how can i produce message?

use bin/pulsar proxy command and first write conf/proxy.conf， but get error:

17:45:28.322 [main] ERROR org.apache.pulsar.proxy.server.ProxyServiceStarter - Failed to start pulsar proxy service. error msg Failed to bind Pulsar Proxy on port 6650

how can i operate?

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zookeeperServers=huwenhao02-dev.bcc-bdbl.baidu.com

# Configuration store connection string (as a comma-separated list)
the machine a (run a standalone on machine a) dns name replace ****
configurationStoreServers=***:2181

# if Service Discovery is Disabled this url should point to the discovery service provider.
brokerServiceURL=pulsar://***:6650
brokerServiceURLTLS=pulsar+ssl://***:6651

# These settings are unnecessary if `zookeeperServers` is specified
brokerWebServiceURL=http://***:8080
brokerWebServiceURLTLS=https://***:8443
**Describe the solution you'd like**

**Describe alternatives you've considered**

**Additional context**

Start with the bin/pulsar proxy command and conf/proxy.conf, then inspect the reported ProxyServiceStarter bind failure on port 6650. Done means documenting the required proxy configuration and the steps for producing from machine B to the standalone Pulsar instance on machine A.

Written by the indexing model from the issue text.