Change wordpress blog poss rewrite rules

wp-rewrite.php

<?php
/*
|--------------------------------------------------------------------------
| Fix for blog links
|--------------------------------------------------------------------------
| Add post type before single post name (fix post link on backend)
*/
function fix_blog_links($post_link, $post, $leavename) {

   if($post->post_status === 'draft') return $post_link;
   // We're adding this rule to only posts, you can ofc maniplutate it as you wish :)
   if($post->post_type !== 'post') return $post_link;

   $configSlugs = 'blog;

   // without %postname% edit permalink will not appear in backend
   if($leavename){
    return home_url('/'.$post_page_slug.'/%postname%/');
   }else{
       return home_url('/'.$post_page_slug.'/'.$post->post_name);
   }
}

add_filter('post_link', 'fix_blog_links', 1, 3);

Missing a ' on line 14

Also, this doesn't work for me. Permalink set to /%postname%/

Nothing gets updated/rewritten~

Line 14 should read $post_page_slug = 'blog';