Post multipage not showing navigation

This plugin works great at homepage, hueman theme without need to change the code or whatever. But when I check one of my post that actually have page split, It didn’t show the page number.

Then yesterday morning (UTC+7 here) I fiddling with single-tmpl.php of hueman theme to change certain code that I think convert wppagenavi (default hueman theme support) to current pagination plugin. OFC I just copy paste from your plugin recommendation. This line that I changed to.

          <nav class="pagination group">
            <?php
              //Checks for and uses wp_pagenavi to display page navigation for multi-page posts.
              if ( function_exists( 'pgntn_display_pagination' ) ) pgntn_display_pagination( 'multipage' );
              else
                wp_link_pages(array('before'=>'<div class="post-pages">'.__('Pages:','hueman'),'after'=>'</div>'));
            ?>
          </nav><!--/.pagination-->

And it still didn’t work. I’m not sure what is wrong. Not even default wordpress “next page” is showing. I’m sure that page got split. Try add page number from url, it will show next page.

I need solution. Thank you.

Summary:
Plugin work great at homepage without inserting any code php.

Plugin didn’t work in post with multipage.

I try inserting the code, still not showing. Everything seems fine, no white screen of death, code should inserted properly but not working.

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