<!-- BEGIN COPY / PASTE -->
    // Register a dynamic block
    function my_dynamic_block_init() {
        register_block_type('my-plugin/my-dynamic-block', array(
            'render_callback' => 'my_dynamic_block_render',
        ));
    }
    add_action('init', 'my_dynamic_block_init');

    // Server-side rendering function
    function my_dynamic_block_render($attributes) {
        $dynamic_content = get_option('my_dynamic_content_option', 'Default Content');
        return '<div class="my-dynamic-block">' . esc_html($dynamic_content) . '</div>';
    }
    <!-- END COPY / PASTE -->