How to subscribe to remote other app

1

AppB subscribe to AppA result data empty

// ------ App A -------
// run http://localhost:3000

//bookCollection.js
import { Mongo } from "meteor/mongo";
const BookCollection = new Mongo.Collection("bookCollection");
export default  BookCollection;

//publish.js
import { Meteor } from "meteor/meteor";
import BookCollection from './bookCollection';

Meteor.publish('books', function () {
   return BookCollection.find({});
}

// --------- App B ---------
// run http://localhost:5000

//index.js client
import { Meteor } from "meteor/meteor";
Meteor.connection = DDP.connect('http://127.0.0.1:3000');

//colletions.js
import { Meteor } from "meteor/meteor";
import { Mongo } from "meteor/mongo";
import { DDP } from "meteor/ddp-client";

export const BookCollection = new Mongo.Collection("bookCollection",{connection:Meteor.connection});
export const CategoryCollection = new Mongo.Collection("categoryCollection",{connection:Meteor.connection});

//main.vue

import { BookCollection } from './colletions'

mounted(){
  let handle = Meteor.connection.subscribe('books');
  if(handle.ready()){
      console.log(BookCollection.find({}).fetch());
     // result empty
  }
}

BookCollection cannot get data from remote App A
How to config subscribe

Thank you.