How can I display thumbnails and their respective categories in a WordPress menu using wp_nav_walker?

Question

I'm designing a WordPress theme, I'm having trouble designing a menu and I can't display the thumbnail and its category.

This is my walker file:

<?php
/**
 * Class Name: wp_bootstrap_navwalker_list_super
 * GitHub URI: https://github.com/twittem/wp-bootstrap-navwalker
 * Description: A custom WordPress nav walker class to implement the Twitter Bootstrap 2.3.2 navigation style in a custom theme using the WordPress built in menu manager.
 * Version: 1.4.5
 * Author: Edward McIntyre - wpdesigner.ir
 * License: GPL-2.0+
 * License URI: http://www.gnu.org/licenses/gpl-2.0.txt
 *Share by: http://wpdesigner.ir
 */
$args_1 = array(
  'orderby' => 'name',
  'order' => 'ASC',
  'parent' => 0
);

class wp_bootstrap_navwalker_list_super extends Walker_Nav_Menu {
  
    /**
     * @see Walker::start_lvl()
     * @since 3.0.0
     *
     * @param string $output Passed by reference. Used to append additional content.
     * @param int $depth Depth of page. Used for padding.
     */
    function start_lvl( &$output, $depth = 0, $args = array() ) {
        $indent = str_repeat("\t", $depth);
        $output .= "\n$indent<ul class=\" dropdown-menu\">\n";
    }

    /**
     * @see Walker::start_el()
     * @since 3.0.0
     *
     * @param string $output Passed by reference. Used to append additional content.
     * @param object $item Menu item data object.
     * @param int $depth Depth of menu item. Used for padding.
     * @param int $current_page Menu item ID.
     * @param object $args
     */

    function start_el( &$output, $item, $depth = 0, $args = array(), $id = 0 ) {
        $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

        /**
         * Dividers & Headers
         * ==================
         * Determine whether the item is a Divider, Header, or regular menu item.
         * To prevent errors we use the strcasecmp() function to so a comparison
         * that is not case sensitive. The strcasecmp() function returns a 0 if 
         * the strings are equal.
         */
        if (strcasecmp($item->title, 'divider') == 0) {
            // Item is a Divider
            $output .= $indent . '<li class="divider">';
        } else if (strcasecmp($item->title, 'divider-vertical') == 0) {
            // Item is a Vertical Divider
            $output .= $indent . '<li class="divider-vertical">';
        } else if (strcasecmp($item->title, 'nav-header') == 0) {
            // Item is a Header
            $output .= $indent . '<li class="nav-header">' . esc_attr( $item->attr_title );
        } else {

            $class_names = $value = '';

            $classes = empty( $item->classes ) ? array() : (array) $item->classes;
            $classes[] = 'menu-item-' . $item->ID;

            $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args ) );
            
            //If item has_children add dropdown class to li
            if($args->has_children) {
                $class_names .= ' dropdown';
            }

            $class_names = $class_names ? ' class="' . esc_attr( $class_names ) . '"' : '';

            $id = apply_filters( 'nav_menu_item_id', 'menu-item-'. $item->ID, $item, $args );
            $id = $id ? ' id="' . esc_attr( $id ) . '"' : '';

            $output .= $indent . '<li'  .'>';

            $atts = array();
            $atts['title']  = ! empty( $item->title )      ? $item->title      : '';
            $atts['target'] = ! empty( $item->target )     ? $item->target     : '';
            $atts['rel']    = ! empty( $item->xfn )        ? $item->xfn        : '';

            //If item has_children add atts to a
            if($args->has_children) {
                $atts['href']           = '#';
                $atts['class']          = 'dropdown-toggle';
                $atts['data-toggle'] = 'dropdown';
                $atts['data-target'] = '#';
            } else {
                $atts['href'] = ! empty( $item->url ) ? $item->url : '';
            }

            $atts = apply_filters( 'nav_menu_link_attributes', $atts, $item, $args );

            $attributes = '';
            foreach ( $atts as $attr => $value ) {
                if ( ! empty( $value ) ) {
                    $value = ( 'href' === $attr ) ? esc_url( $value ) : esc_attr( $value );
                    $attributes .= ' ' . $attr . '="' . $value . '"';
                }
            }

            $item_output = $args->before;
        
            /*
             * Glyphicons
             * ===========
             * Since the the menu item is NOT a Divider or Header we check the see
             * if there is a value in the attr_title property. If the attr_title
             * property is NOT null we apply it as the class name for the glyphicon.
             */

            if(! empty( $item->attr_title )){
                $item_output .= '<a'. $attributes .'title="دانلود تمام آهنگ ها"'.'><i class="' . esc_attr( $item->attr_title ) . '"></i>&nbsp;';
                $show_list = 1;
            } else {
                $item_output .= '<a'. $attributes .'>';
            }
            

            $item_output .= $args->link_before .'<img width="150" height="150" src="'.get_the_post_thumbnail_url().'" class="attachment-thumbnail size-thumbnail wp-post-image" alt="دانلود آهنگ امین نیک میشه بخندی" decoding="async" title="'.$item->description.the_title().'" loading="lazy"><span><strong>'.apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after.'</strong><strong>'.wpb_get_id_terms_category(apply_filters( 'the_category', $item->ID ))."</strong>";
            $item_output .= ($args->has_children) ? ' <span class="caret"></span></a>' : /*.the_title().'</strong><strong>'.*/'</strong></span></a>';
            $item_output .= $args->after;
            $show_list = 1;
            $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
        }
    }

    /**
     * Traverse elements to create list from elements.
     *
     * Display one element if the element doesn't have any children otherwise,
     * display the element and its children. Will only traverse up to the max
     * depth and no ignore elements under that depth. 
     *
     * This method shouldn't be called directly, use the walk() method instead.
     *
     * @see Walker::start_el()
     * @since 2.5.0
     *
     * @param object $element Data object
     * @param array $children_elements List of elements to continue traversing.
     * @param int $max_depth Max depth to traverse.
     * @param int $depth Depth of current element.
     * @param array $args
     * @param string $output Passed by reference. Used to append additional content.
     * @return null Null on failure with no changes to parameters.
     */

    function display_element( $element, &$children_elements, $max_depth, $depth, $args, &$output ) {
        if ( !$element ) {
            return;
        }

        $id_field = $this->db_fields['id'];

        //display this element
        if ( is_object( $args[0] ) ) {
           $args[0]->has_children = ! empty( $children_elements[$element->$id_field] );
        }

        parent::display_element($element, $children_elements, $max_depth, $depth, $args, $output);
    }
}

?>

And this function is wpb_get_id_terms_category which is located in functions.php

function wpb_get_id_terms_category($taxonomy)
{
    $currentPost =  the_category('','',$taxonomy);
    /*
    $terms       = get_the_terms($currentPost->ID, $taxonomy);

    if (is_wp_error($terms)) {
       // @var \WP_Error $terms 
        throw new \Exception($terms->get_error_message());
    }

    $map = array_map(
        function ($term) use ($taxonomy) {
            return esc_attr($term->name);
        },
        array_filter($terms, function ($term) {
            return $term->parent == 0;
        })
    );
    */
    return $currentPost;
}

But unfortunately, it does not work properly and only the thumbnail of the first post and the first post category are displayed for all lists