Question: gRPC client call

[Mai Reaksa]

Dear, gRPC team. I have one question, i build gRPC sever with dart and client dart also, when i went call from gRPC server without proto file i can not sent request and get data i just connect sever. How can i don call server because my client using mobile flutter. 
This my code client:

 import 'package:grpc/grpc.dart';

Future<void> main(List<String> args) async {

final channel = ClientChannel(

'localhost',

port: 50051,

options: const ChannelOptions(credentials: ChannelCredentials.insecure()),

);

try {

channel.getConnection();

print("Connectino Done");

} catch (e) {

print("object");

}

}