Cannot index existing data from mongo to elastic using mongoose

Question

I'm trying to index data from mongo DB to elasticsearch using mongoose, my documents are already existing or maybe there is a way to indexing all data automatically without a schema please help me!

This is my document:

This is my node code:

const mongoose     = require('mongoose');
const mongoosastic = require('mongoosastic');

mongoose.connect('mongodb://localhost:27017/landingZoneDB');


var commentsSchema=new mongoose.Schema({
    joined_date:{type:String} ,
 comment_date:{type:String}, 
    comment_body:{type:String},user_link:{type:String} ,
    posts_count:{type:String}, user_name:{type:String}});


var DNMAvengers_tbSchema = new mongoose.Schema({
    crawl_date:{type:String}
    , views:{type:String}
    , replies:{type:String}
    ,title:{type: String}
    ,comments: [commentsSchema] 
    ,link:{type: String}
    ,forum_title:{type: String}
    ,avatar_details: {avatar_name:{type: String} ,avatar_pass:{type: String}, avatar_user:{type:String}, avatar_email:{type: String} }
});

var comments = mongoose.model('comments', commentsSchema);


DNMAvengers_tbSchema.plugin(mongoosastic);

var DNMAvengers_tb = mongoose.model('DNMAvengers_tb', DNMAvengers_tbSchema)
  , stream = DNMAvengers_tb.synchronize()
  , count = 0;

var stream = DNMAvengers_tb.synchronize({}, {saveOnSynchronize: true})

stream.on('data', function(err, doc){
  count++;
});
stream.on('close', function(){
  console.log('indexed ' + count + ' documents!');
});

stream.on('error', function(err){
  console.log(err);
});

That my result:

C:\Users\Administrator>node RUN.js (node:2816) DeprecationWarning: current URL string parser is deprecated, and will be removed in a future version. To use the new parser, pass option { useNewUrlParser: true } to MongoClient.connect. (node:2816) DeprecationWarning: current Server Discovery and Monitoring engine is deprecated, and will be removed in a future version. To use the new Server Discover and Monitoring engine, pass option { useUnifiedTopology: true } to the MongoClient constructor. indexed 0 documents!