Where to add html for easy slider?

Hi, i would like to customize the layer slider, with a back button and own navigation-icons.
Where can i add this code

<div class="easy-slider-wrapper">
    <div class="easy-slider">
        <?php echo do_shortcode('[av_slideshow ...]'); // Easy Slider Shortcode ?>
    </div>
    <div class="custom-nav-container">
        <a href="https://mydomain/move-layer-3/" class="custom-nav-link custom-left-link">
            <img src="https://mydomain/wp-content/uploads/2024/06/WB-Nav-Arrow-Left.svg" alt="Left">
        </a>
        <a href="https://mydomain/move-layer-3/" class="custom-nav-link custom-close-link">
            <img src="mydomain/wp-content/uploads/2024/06/WB-Nav-X.svg" alt="close">
        </a>
        <a href="https://mydomain/move-layer-4-01-02/" class="custom-nav-link custom-right-link">
            <img src="mydomain/wp-content/uploads/2024/06/WB-Nav-Arrow-Right.svg" alt="Right">
        </a>
    </div>
</div>

`I was thinking about copying the template-builder.php and adding it in the enfold-child folder, but i’m not sure, if template-builder.php is correct?
kind regards
Jak