daimaku

i tried to follow your instructions, i have downloaded the page.php from my theme and i have added my custom code after the page code and before the end of the page, like this:

<?php /* Template Name: CustomPageT1 */ ?>
<?php get_header(); ?>
	<div id="primary" class="content-area">

	    <main id="main" class="site-main" role="main">

	        <?php

	        // Start the loop.

	        while ( have_posts() ) : the_post();

	            // Include the page content template.

	            get_template_part( 'template-parts/content', 'page' );

	 
	            // If comments are open or we have at least one comment, load up the comment template.
	            if ( comments_open() || get_comments_number() ) {
	                comments_template();
	            }
	 
	            // End of the loop.
	        endwhile;
	        ?>

	    	    </main><!-- .site-main -->
	 
	    <?php get_sidebar( 'content-bottom' ); ?>
	 
	</div><!-- .content-area -->
	<!-- custom code -->
	<?php
        $title_add="testing php post";
        $content_add="<p align='justify'>just testing the add post using custom php</p>";

        // Create post object
        $my_post = array(
           'post_id'	   => 22,
           'post_title'    => $title_add,
           'post_content'  => $content_add,
           'post_status'   => 'publish',
           'post_author'   => 1,
           'post_category' => array( 8,39 )
        );

        // Insert the post into the database
        wp_insert_post( $my_post );
        add_post_meta(22,'_testing_post_meta_add','just text to let see if this is working');
    
        function add_post_meta( $post_id, $meta_key, $meta_value, $unique = false ) {
             // Make sure meta is added to the post, not a revision.
            if ( $the_post = wp_is_post_revision($post_id) )
                $post_id = $the_post;
             return add_metadata('post', $post_id, $meta_key, $meta_value, $unique);
        }
    ?>
    <!-- end custom code -->

	<?php get_sidebar(); ?>

	<?php get_footer(); ?>

but it didn’t work, any help or tip will be very useful.

thanks in advance!