Unimplemented desc = Method not found: eventmesh.common.protocol.grpc.PublisherService/publish

### Search before asking

- [ ] I had searched in the [issues](https://github.com/apache/eventmesh/issues?q=is%3Aissue) and found no similar issues.

### Question

When I try to run the grpc example in the example, the log shows that the grpc connection is successful, but it also shows that Method not found. I don't quite understand how to deal with this problem. Can anyone tell me?

Locate the gRPC example and the PublisherService/publish method named in the report. Run the example and trace the service and method declaration to determine why the server returns “Method not found.” Done means the example connects and publishes without this error.

Written by the indexing model from the issue text.