Attributes in a Dynamic Custom Block

How do you access $attributes from a dynamic custom block PHP file?

Accessing attributes in a static custom block via JS is really simple. However I’m unable to access attributes in a dynamic custom block via PHP.

I’m using the @wordpress/create-block (@wordpress/scripts v25.1.0) to get started with dynamic blocks:

npx @wordpress/create-block --variant dynamic todo-list

In this latest version, you are provided with a render.php file. Not sure how you are meant to return the attributes within this file. Can’t find any docs on this:

<?php

global $block;

$attributes = $block['attrs'];
// $attributes = $block->get_attributes();

print_r($attributes);

?>
<div <?php echo get_block_wrapper_attributes(); ?>>
	<?php esc_html_e('My Dynamic Block – hello from a dynamic block!', 'my-dynamic-block'); ?>
</div>

Failing that, I’ve gone back into the main php where the block is registered and have tried hooking into the render_callback since this should be able to return the attributes , content and block:

function register_dynamic_block()
{
    register_block_type(
        __DIR__ . '/build',
        array('render_callback' => 'my_callback')
    );
}
add_action('init', 'register_dynamic_block');

function my_callback($attributes, $content, $block)
{
    print_r($attributes); 
   // Can't even access attributes in here! :S
}

But this also just prints an empty array Array()

Anyone have any ideas as to how you are meant to retrieve attributes from the render.php file?