the widget was work correctly on odoo 12 but in odoo 13 the button where fire the widget dont give any action and after trace error i found thet the init function is fired correctly but start function not work

 iremoved part of the code which have events

odoo.define("stock_scan_frontend.action_start_scanning", function(require) {
console.log("begin");
    "use strict";
    var core = require("web.core");
    var Widget = require("web.Widget");
    var _t = core._t;
    var QWeb = core.qweb;
    var rpc = require('web.rpc');

    var ScanningModel = Backbone.Model.extend({
        initialize: function (session, attributes) {
        console.log("1");

            var self = this;
            this.active_id = this.get_stock_id();
            this.ready = this.load_stock_data();
            this.data = {};
            this.quantsData = {};
            this.products = {};
            this.codeProducts = {}
            this.scan_lines = {}
            this.addedScansObj = {};
            this.totalQty = 0;
            this.createdScansObj = {};
            this.type_of_scaning = '';
            this.pickin_Typ_code = '';
        },
        get_stock_id: function () {
        console.log("2");
            var lochash = location.hash.substr(1);
            var activeid = lochash.substr(lochash.indexOf('id='))
                    .split('&')[0]
                    .split('=')[1];
            return activeid;
        },
        load_stock_data: function () {
        console.log("3");
            var loaded = new $.Deferred();
            var self = this;
            var stock_picking = rpc.query({
                model:'stock.picking',
                method: 'get_stock_lot_scan_data',
                args: [self.active_id],
            }).then(function (result) {
            console.log("4");
                result = JSON.parse(result);
                console.log(result);
                self.scan_lines = result.scan_lines;

                self.data = result.data;
                self.products = result.products;
                self.codeProducts = result.productsCodeData;
                self.type_of_scaning = result.type_of_scaning;
                self.pickin_Typ_code = result.pickin_Typ_code;
                self.res_id = result.res_id;

                loaded.resolve();


            });
console.log("4aaxx");
            return loaded;
        }
    });
var Scanning = Widget.extend({
    template: "Scanning",
    xmlDependencies: ['/stock_scan_frontend/static/xml/stock.xml'],
init: function (parent) {
console.log("7");
    this._super(parent);
    this.stock_data = new ScanningModel(require);
    console.log("7a");
},
start: function () {
console.log("8");
    var sup = this._super();
    var self = this;
          this._super.apply(this, arguments);


    return this.stock_data.ready.done(function () {
        self.$el.prepend();
        setTimeout(function () {
            $('input#scan_box').focus();
            if (self.stock_data.type_of_scaning == 'third_group') {
                $('input#default_code').show().focus();
                $('input#expiration_date').show();
            } else {
                $('input#default_code').remove();
                $('input#expiration_date').remove();
                $('input#scan_box').attr('style', '');
            }

            var scan_lines_count = Object.keys(self.stock_data.scan_lines).length;
            if (scan_lines_count > 0) {
                for (var i = 0; i < scan_lines_count; i++) {
                    var scan_box = self.stock_data.scan_lines[i]['serial'];
                    if (!self.stock_data.addedScansObj[scan_box]) {
                        self.stock_data.addedScansObj[scan_box] = {};
                    }
                    var encoded = CryptoJS.MD5(scan_box);
                    var qty = parseInt(self.stock_data.scan_lines[i]['qty']);
                    var product_id = self.stock_data.scan_lines[i]['product_id'];
                    var product = self.stock_data.products[product_id]
                    var lot_name = self.stock_data.scan_lines[i]['lot_name'];
                    var date = new Date(self.stock_data.scan_lines[i]['expiration_date']);
                    self.stock_data.addedScansObj[scan_box][product_id] = {'stock_picking_id': parseInt(self.stock_data.res_id), 'product_id': product['id'], 'product_uom_qty': qty, 'lot_no': scan_box, 'lot_name': lot_name, 'expiration_date': self.stock_data.scan_lines[i]['expiration_date']};
                    var html = '<tr id="' + encoded + '"><td><input type="hidden" class="lineProductId" value="' + product['id'] + '" />' + product['name'] + '</td><td><input type="number" class="qty" value="' + qty + '"/></td><td><span class="scan_box_line">' + scan_box + '</span></td><td>' + lot_name + '</td><td>' + $.datepicker.formatDate("mm/dd/yy", date) + '</td><td style="cursor:pointer;" class="deleteScan"><span class="fa fa-trash-o" name="delete"></span></td></tr>';
                    $('table tbody').append(html);
                    self.stock_data.totalQty += qty;
                }
                $('span.totalQty').html(self.stock_data.totalQty);
            }
        }, 1000);
    });
},

    });
  //  instance.web.client_actions.add('stock.scan', 'instance.stock_scan_frontend.Scanning');
    core.action_registry.add("stock.scan", Scanning);

});