<!-- BEGIN COPY / PASTE -->
    // JavaScript: Register the block
    wp.blocks.registerBlockType('myplugin/dynamic-block', {
      title: 'Dynamic Block',
      category: 'widgets',
      edit: function() {
        return wp.element.createElement('p', {}, 'Dynamic content will appear here.');
      },
      save: function() {
        return null; // Server-side rendering
      }
    });

    // PHP: Render the block dynamically
    function myplugin_render_dynamic_block($attributes) {
      $dynamic_content = 'This is dynamic content generated by PHP.';
      return '<p>' . esc_html($dynamic_content) . '</p>';
    }
    register_block_type('myplugin/dynamic-block', array(
      'render_callback' => 'myplugin_render_dynamic_block',
    ));
    <!-- END COPY / PASTE -->