Thank you very much!
You will have to edit your theme’s single.php file. I suggest that you create a child theme, because if you do not do so, when you update the theme, it is most likely that this edit we are going to do here, will be lost. You can find a great article on how to create the child theme here:
codex.wordpress.org/Child_Themes
After you have created the child theme folder and made the necessary edits to the style.css folder as the above article suggests, please copy the single.php file from the wp-content/themes/hueman/ folder to your child theme’s folder, and edit this file there (so not in the parent’s folder).
In the single.php file, please find this part, it is on the beginning of the file, around line number 14
<?php while ( have_posts() ): the_post(); ?>
<article <?php post_class(); ?>>
<div class="post-inner group">
<h1 class="post-title"><?php the_title(); ?></h1>
<p class="post-byline"><?php _e('by','hueman'); ?> <?php the_author_posts_link(); ?> · <?php the_time(get_option('date_format')); ?></p>
<?php get_template_part('inc/post-formats'); ?>
And insert there the row
<p class="post-byline"><?php the_subtitle(); ?></p>
So at the end, it should look like this:
<?php while ( have_posts() ): the_post(); ?>
<article <?php post_class(); ?>>
<div class="post-inner group">
<h1 class="post-title"><?php the_title(); ?></h1>
<p class="post-byline"><?php the_subtitle(); ?></p>
<p class="post-byline"><?php _e('by','hueman'); ?> <?php the_author_posts_link(); ?> · <?php the_time(get_option('date_format')); ?></p>
<?php get_template_part('inc/post-formats'); ?>
Save the file, and reload your website.
Please let me know if this solved your problem.
If you have any additional questions, just drop a line here and I am happy to help you.
Greetings,
Toth Balint BT