unable to displaying category image in my creating module

i want to display caregory images in my own module , so i create a module and frontend/templates/category-section.phtml , and this is the code , my problem is the source image is empty ,it returns null in my creating page ,all others properties like this works correctly

i uploaded the image in admin panel and when i click on the a tag it return the category pages with the image correctly but only in my displaying categories and images , the images arent displaying

the images here arent displayed

if i click on any one, the url and image exist here but in new module arent

<?php echo $category->getName() ?>

<section class="section-holder">
    <div class="all-categories">
        <p class='category-text'>categories</p>
        <div class='categories-flex'>
            <?php
            $categoryHelper = $this->helper('MagentoCatalogHelperCategory');
            $outputhelper   = $this->helper('MagentoCatalogHelperOutput');


            foreach ($categoryHelper->getStoreCategories() as $category) :

            ?>
                <a href="<?php echo $categoryHelper->getCategoryUrl($category) ?>">
                    <div class='child-category'>
                        <div>
                            <img style="background-image: url('<?= $category->getImageUrl();  ?>');" alt="">
                        </div>

                        <p> <?php echo $category->getName() ?></p>
                    </div>
                </a>
            <?php
            endforeach;
            ?>
        </div>
    </div>
</section>