Howdy!
You can disable automatic output in Helpful’s preferences and place the shortcode into the content by hand.
To do this, go to Helpful -> Settings -> General -> Hide Helpful in post content
Then you can place the shortcode by hand, or do the following (functions.php):
<?php
/**
* Place the Helpful Shortcode automatically after the content.
*
* @see https://helpful-plugin.info/documentation/shortcodes/
*
* @param string $content The current content of the post.
* @return string
*/
function custom_add_helpful_after_the_content( $content ) {
global $post;
$post_type = 'post';
/* only in singles and post type "post" */
if ( is_singular() && $post->post_type === $post_type ) {
$helpful_shortcode = do_shortcode( '[helpful heading="My new heading!" post_id="' . $post->ID . '"]' );
}
return $content . $helpful_shortcode;
}
add_filter( 'the_content', 'custom_add_helpful_after_the_content', PHP_INT_MAX );
Hopefully this could help you a bit.