Calling api client to modify the data of parent api client call

client.post(config.apiUrl+"cart", args, function(data,response) {

                if (data.status == 'success') {

                    for (var key in data.data.cart_items_list) {
                       if (data.data.cart_items_list.hasOwnProperty(key)) {

                            data.data.cart_items_list[key].child.prodqty = function () {
                                client.get(config.apiUrl+"product/"+data.data.cart_items_list[key].child.child_id+"/quantity",  function(invdata, invresponse) {

                                    if(invdata.status == 'success'){
                                        console.log(invdata.data);
                                        return invdata.data;

                                        console.log(data.data.cart_items_list[key].child.prodqty);
                                    }
                                })
                            }
                       }
                    }

                    console.log(data.data.cart_items_list);
                }

        })

Above is piece of code I have written to get one modify the data I got from api client call. The first api call will a json data. I am looping thru that data to get one value from another api and append to parent's json data

console.log(data.data.cart_items_list[key].child.prodqty); line prints the correct value in my logs, but console.log(data.data.cart_items_list); this is not having the newly(child.prodqty) appended value in it.

I am very much new in Node.js so I don't know whether I am doing it correct