Elementor wont load a post editor

Hi, I’m trying to use elementor to edit my single post pages. I created my own theme and wanted implement Elementor, but when i try to edit with elementor the error “The preview could not be loaded” occurs. Can’t figure out to solve it.

this is the code of my single.php
<?php
/*Template Name: TemplatePost
Template Post Type: post
*/
get_header();?>
<div class=”content-post”>
<?php the_content(); ?>
</div>

<?php get_footer(); ?>