Custom widget doesn't work in customizer

Hi, I have working widget on the dashboard, which can upload images. My source was here, but in customizer the Upload image button doesn’t work. The scripts are loaded, can alert a message on click, and also tb_show() function doesn’t work on click. Here is the code:

class My_Widget extends WP_Widget {
    function __construct() {
        parent::__construct(
                'my_widget',
                __('My Widget', 'my_theme'),
        );
        add_action('admin_enqueue_scripts', array($this, 'upload_scripts'));
    }

    public function upload_scripts() {
        global $pagenow;
        if($pagenow == 'widgets.php' || $pagenow == 'customize.php') {
            wp_enqueue_script('media-upload');
            wp_enqueue_script('thickbox');
            wp_enqueue_script('upload_media_widget', get_template_directory_uri() . '/js/upload-media.js', array('jquery'));
            wp_enqueue_style('thickbox');
        }
    }

    public function widget($args, $instance) {
        echo $args['before_widget'];
        ?>
        <a href="<?php echo $instance['link']; ?>" title="<?php echo $instance['title']; ?>" target="_blank">
            <div style="background-image: url(<?php echo $instance['image']; ?>)">
                <h2><?php echo $instance['title']; ?></h2>
            </div>
            <p><?php echo $instance['description']; ?></p>
        </a>
        <?php
        echo $args['after_widget'];
    }

    public function form($instance) {
        $title = !empty($instance['title']) ? $instance['title'] : '';
        $description = !empty($instance['description']) ? $instance['description'] : '';
        $link = !empty($instance['link']) ? $instance['link'] : '';
        $image = !empty($instance['image']) ? $instance['image'] : '';
        ?>
        <p>
            <label for="<?php echo $this->get_field_id('title'); ?>"><?php _e('Title:'); ?></label>
            <input class="widefat" id="<?php echo $this->get_field_id('title'); ?>" name="<?php echo $this->get_field_name('title'); ?>" type="text" value="<?php echo esc_attr($title); ?>">
        </p>
        <p>
            <label for="<?php echo $this->get_field_id('description'); ?>"><?php _e('Description:'); ?></label>
            <textarea class="widefat" id="<?php echo $this->get_field_id('description'); ?>" name="<?php echo $this->get_field_name('description'); ?>"><?php echo esc_attr($description); ?></textarea>
        </p>
        <p>
            <label for="<?php echo $this->get_field_id('link'); ?>"><?php _e('Link:'); ?></label>
            <input class="widefat" id="<?php echo $this->get_field_id('link'); ?>" name="<?php echo $this->get_field_name('link'); ?>" type="text" value="<?php echo esc_attr($link); ?>">
        </p>
        <p>
            <label for="<?php echo $this->get_field_name('image'); ?>"><?php _e('Image:'); ?></label>
            <input name="<?php echo $this->get_field_name('image'); ?>" id="<?php echo $this->get_field_id('image'); ?>" class="widefat" type="text" size="36"  value="<?php echo esc_url($image); ?>" />
            <input class="js-upload-image-button" type="button" value="Upload Image" />
        <?php
    }

    public function update($new_instance, $old_instance) {
        $instance = array();
        $instance['title'] = (!empty($new_instance['title']) ) ? strip_tags($new_instance['title']) : '';
        $instance['description'] = (!empty($new_instance['description']) ) ? strip_tags($new_instance['description']) : '';
        $instance['link'] = (!empty($new_instance['link']) ) ? strip_tags($new_instance['link']) : '';
        $instance['image'] = (!empty($new_instance['image']) ) ? strip_tags($new_instance['image']) : '';

        return $instance;
    }

}

function register_my_widget() {
    register_widget('My_Widget');
}
add_action('widgets_init', 'register_my_widget');

And here is upload-media.js :

jQuery(document).ready(function($) {
    $(document).on("click", ".js-upload-image-button", function() {
        jQuery.data(document.body, 'prevElement', $(this).prev());
        window.send_to_editor = function(html) {
            var imgurl = jQuery('img',html).attr('src');
            var inputText = jQuery.data(document.body, 'prevElement');

            if(inputText != undefined && inputText != '')
            {
                inputText.val(imgurl);
            }

            tb_remove();
        };
        tb_show('', 'media-upload.php?type=image&TB_iframe=true');
        return false;
    });
});

Thanks for help.