How to display an image in the Carbon Fields plugin

Good morning, can you tell me how to display an image in a block? it does not work, it is not even added in the edit, i.e. you put it, update it, and it disappears, and the text remains, why is this happening? I attach the code

<?php
use Carbon_Fields\Container;
use Carbon_Fields\Field;

add_action( 'carbon_fields_register_fields', 'crb_attach_theme_options' );
function crb_attach_theme_options() {
    Container::make( 'post_meta', 'Заметки автора статьи' )
             ->add_fields( array(
                            Field::make( 'complex', 'fio', 'Соавторы статьи' )
                                ->add_fields( array(
                                    Field::make( 'textarea', 'case_title', 'Заголовок кейса' ),
                                    Field::make( 'text', 'case_item-text-1', 'Заголовок первой колонки' ),
                                    Field::make( 'text', 'case_item-text-2', 'Заголовок второй колонки' ),
                                    Field::make( 'text', 'case_item-text-3', 'Заголовок третьей колонки' ),
                                    Field::make( 'text', 'case_item-text-sub-1', 'Цифры' ),
                                    Field::make( 'text', 'case_item-text-sub-2', 'Цифры 2' ),
                                    Field::make( 'text', 'case_item-text-sub-3', 'Цифры 3' ),
                                    Field::make( 'text', 'case_what-done', 'Что сделано' ),
                                    Field::make( 'text', 'case_what-done-1', 'Что сделано - первый пункт' ),
                                    Field::make( 'text', 'case_what-done-2', 'Что сделано - второй пункт' ),
                                    Field::make( 'text', 'case_what-done-3', 'Что сделано - третий пункт' ),
                                    Field::make( 'text', 'case_what-done-4', 'Что сделано - четвертый пункт' ),
                                    Field::make( 'text', 'case_what-done-5', 'Что сделано - пятый пункт' ),
                                    Field::make( 'image', 'photo', 'Картинка' ),
                                 )
                                )
                    ) );
}

                <?php

                $blocks = carbon_get_post_meta( $post->ID, 'fio');
                $thumbnail_id = carbon_get_term_meta( 'image', 'photo');
                $thumbnail_url = wp_get_attachment_image_url( $thumbnail_id, 'full' );
                ?>


                <?php
                if ( ! empty( $blocks ) ): ?>
                    <?php foreach ( $blocks as $div ): ?>
                      <div class="results-case ">
                        <div class="results-case__text">
                            <h3 class="results-case__title">
                                <?php echo $div['case_title'] ?>
                                <img src="<?php echo $thumbnail_url; ?>" alt="" />
                            </h3>
                            <div class="results-case__items">
                                <div class="results-case__item results-case__item-1">
                                    <span class="results-case__item-title"><?php echo $div['case_item-text-1'] ?></span>
                                    <span class="results-case__item-desc"><?php echo $div['case_item-text-sub-1'] ?></span>
                                </div>
                                <div class="results-case__item results-case__item-2">
                                    <span class="results-case__item-title"><?php echo $div['case_item-text-2'] ?></span>
                                    <span class="results-case__item-desc"><?php echo $div['case_item-text-sub-2'] ?></span>
                                </div>
                                <div class="results-case__item results-case__item-3">
                                    <span class="results-case__item-title"><?php echo $div['case_item-text-3'] ?></span>
                                    <span class="results-case__item-desc"><?php echo $div['case_item-text-sub-3'] ?></span>
                                </div>
                            </div>
                            <span class="results-case__list-title"><?php echo $div['case_what-done'] ?></span>
                            <span class="results-case__list-item results-case__list-item-1"><?php echo $div['case_what-done-1'] ?></span>
                            <span class="results-case__list-item results-case__list-item-2"><?php echo $div['case_what-done-2'] ?></span>
                            <span class="results-case__list-item results-case__list-item-3"><?php echo $div['case_what-done-3'] ?></span>
                            <span class="results-case__list-item results-case__list-item-4"><?php echo $div['case_what-done-4'] ?></span>
                            <span class="results-case__list-item results-case__list-item-5"><?php echo $div['case_what-done-5'] ?></span>
                        </div>
                        <div class="results-case-image-block">
                            <img src="<?php echo get_template_directory_uri(); ?>/img/results/result-case-1.png" alt="Картинка сайта" class="results-case__image">
                        </div>
                      </div>
                    <?php endforeach; ?>

                <?php endif; ?>