How to enable comments on pages

Hi,

My page is using the following code in index.php:

<section>
    <?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>
    <h1><?php the_title(); ?></h1>
    <?php the_content(); ?>
    <?php comments_template( '', true ); ?>
    <?php endwhile; else : ?>
    <p><?php _e( 'Sorry, no posts matched your criteria.' ); ?></p>
    <?php endif; ?>
</section>

Settings > Discussion > “Allow people to post comments on new articles” is on.

I am using Disqus comments plugin, and “Disqus comments are currently enabled”.

However, I see “Comments are closed.” at the bottom of every page.

Disqus does work for posts though.

https://www.ads-software.com/plugins/disqus-comment-system/