index.js

var init = function(){
  const grpc = require('@grpc/grpc-js');

  const protoLoader = require('@grpc/proto-loader');

  const PROTO_PATH = __dirname +'/salary.proto';

  const packageDefinition = protoLoader.loadSync(
    PROTO_PATH, { 
     keepCase: true,
     longs: String,
     enums: String,
     defaults: true,
     oneofs: true,
  });

 const paymentProto = grpc.loadPackageDefinition(packageDefinition).employee;

 function main() {
  // Establish connection with the server
  const client = new paymentProto.Employee('X.X.X.X:XXXX', grpc.credentials.createInsecure());
  let employeeIdList = [1,2,3];
  client.paySalary({employeeIdList: employeeIdList} , function(err, response) {
    console.log('Data:', response); // API response
    console.log(err);
   });

  }
  main();
}
exports.init = init;