Is there any way to get post meta from publish_post hook?

Question

I want a post meta of the published post, below is the code but I didn't get it. Appreciate if anyone can help me here:

class BarrioBlog {
    function __construct() {
      add_action( 'publish_post', array( $this, 'on_publish_post' ), 10, 2 );
    }
    function on_publish_post($post_id, $post) {
       echo ' custom field: ' . get_field('channel', $post_id);
       exit;
    }
}

Answer 1

Okay so it was resolved with do_action( 'acf/save_post', $post_id );