I have a schema defined like this

var PersonelModelSchema = new Schema({
  emailAddress: String,
  fullName: String
});

var ModuleModelSchema = new Schema({
  modName: String,
  personels:[PersonelModelSchema ]
});


var ModulesModelSchema=new Schema({
  modules: [ModuleModelSchema ]
});

var ModulesModel = mongoose.model('ModulesModel ', ModulesModelSchema );

This schema is used to save data sent by another app to an api end point built on nodejs

The json data contains an array, the contents of which I want to save as separate documents - ie is the array has 2 objects, each needs to be saved as separate documents. This is the reason I am using array if ModuleModelSchema, so that I can get all the objects in array.

The data that is posted is looks like this

{"modfulldata" :[{
  "modName": "example-45435q5",
  personels: [
    {
      "emailAddress": "name@example",
      "fullName": "name"
    },
    {
      "emailAddress": "name2@example",
      "fullName": "name2"
    }
  ]
},
{
  "modName": "example-f45b",
  personels: [
    {
      "emailAddress": "name3@example",
      "fullName": "name3"
    },
    {
      "emailAddress": "name4@example",
      "fullName": "name4"
    }
  
  ]
}
]}

And this is the code I am using to save

app.post('/savemd', 
    function(req,res){
        console.log(req.body.modfulldata);// the data is shown correctly here

        mongoose.connect(uri, { useNewUrlParser: true, useUnifiedTopology: true, useFindAndModify: false, useCreateIndex: true });
        var db = mongoose.connection;
        db.on('error', console.error.bind(console, 'connection error:'));
        db.once('open', function callback () {
            console.log("open");          

        });

        var newmods=new ModulesModel (req.body.modfulldata);
        
    ModulesModel.insertMany(newmods).then(function(){
                db.close();
        });

    });

There are no errors thrown. With the console.log statement, i can see the request json data is read correctly. However in mongodb, there is only an empty array in the saved document

What am I doing wrong?

How to save the data correctly?