List WordPress pages using a template.

functions.php

<?php

// source: https://paulund.co.uk/list-pages-using-page-template

$args = array(
	'post_type'  => 'page',
	'meta_key'   => '_wp_page_template',
	'meta_value' => 'template-two-column-page.php', // the template you want to check
);

$page_template_query = new WP_Query( $args );

if ( ! empty( $page_template_query->posts ) ) {

	foreach ( $page_template_query->posts as $page ) {
		echo $page->post_title . '<br />';
	}
}