Custom Modal-Window / Promo-Window

Sorry, but you can’t simply replace it in the child theme as it works with default WordPress template files. Try to add the following PHP code snippet to the child theme functions.php file

    function basel_sguide_display_table_template( $sguide_post, $size_tables ){
        $is_quick_view = basel_loop_prop( 'is_quick_view' );
        
        if ( !basel_get_opt( 'size_guides' ) || $is_quick_view || !$size_tables || !$sguide_post ) return;
        
        $sguide_custom_css = get_post_meta( $sguide_post->ID, '_wpb_shortcodes_custom_css', true );
        $show_table = get_post_meta( $sguide_post->ID, 'basel_sguide_hide_table' );
        $show_table = isset( $show_table[0] ) ? $show_table[0] : 'show';
        ?>
            <?php if ( ! empty( $sguide_custom_css ) ): ?>
                <style type="text/css" data-type="vc_shortcodes-custom-css">
                    <?php echo $sguide_custom_css; ?>
                </style>
            <?php endif ?>
            <div id="basel_sizeguide" class="mfp-with-anim basel-content-popup mfp-hide basel-sizeguide">
                <h4 class="basel-sizeguide-title"><?php echo esc_html( $sguide_post->post_title ); ?></h4>
                <div class="basel-sizeguide-content"><?php echo do_shortcode( $sguide_post->post_content ); ?></div>
                <?php if ( $show_table == 'show' ): ?>
                    <div class="responsive-table">
                        <table class="basel-sizeguide-table">
                            <?php foreach ( $size_tables as $table ): ?>
                                <?php foreach ( $table as $row ): ?>
                                    <tr>
                                        <?php foreach ( $row as $col ): ?>
                                            <td><?php echo esc_html( $col ); ?></td>
                                        <?php endforeach; ?>
                                    </tr>
                                <?php endforeach; ?>
                            <?php endforeach; ?>
                        </table>
                    </div>
                <?php endif; ?>
            </div>
            
            <div class="sizeguide-btn-wrapp">
                <a class="basel-popup-with-content basel-sizeguide-btn" href="#basel_sizeguide">
                    <?php echo basel_get_svg_content( 'size-quide-icon' ); ?>
                    <span><?php esc_html_e( 'Size Guide', 'basel' ); ?></span>
                </a>
            </div>
        <?php
    }

and replace this line

<?php echo basel_get_svg_content( 'size-quide-icon' ); ?>

with your SVG file content or with any other icon you want.