You could create a child theme and copy the page.php template to it. Then you adapt this copied file and add the output of the publication date at the place you want but within the while loop. Example
$post_date = get_post_datetime(get_the_ID());
echo $post_date->format('d/m/Y');
Or you add this function in the functions.php of your child theme or via code snippet:
function custom_page_date( $post ) {
$post_date = get_post_datetime($post->ID);
echo $post_date->format('d/m/Y');
}
add_filter( 'the_post', 'custom_page_date');
However, here simply the date is then output above the content. You could refine this at this point and adjust it to your needs.
If you don’t get along with the programming, you can also look for support for your specific case here: https://jobs.wordpress.net/