working render blocks

<?php

/*
Plugin Name: Test Shortcode
Plugin URI: https://fullworks.net
Description: Test Shortcode Gutenberg content
Version: 1.0
Author: alan
Author URI: https://fullworks.net
License: GPL2


*/

if ( ! defined( 'WPINC' ) ) {
	die;
}


add_shortcode( 'test_display', function ( $atts ) {
	$a      = shortcode_atts( array(
		'id' => 0,
	), $atts );
	$return = '';
	$blocks = parse_blocks( get_the_content( null, false, $a['id'] ) );
	foreach ( $blocks as $block ) {
		$return .= apply_filters( 'the_content', render_block( $block ) );
	}

	return $return;
} );