WordPress Permalink Numerical Restoration

I'm currently experiencing issues with my WordPress rewrite script. Specifically, the permalinks for custom post-types are not being rewritten correctly. Here's what I'm looking for: - Expertise with WordPress script troubleshooting. - Experience with rewriting permalinks for custom post-types, which in my case, are the 'Posts'. - Ability to reshape the permalinks structure to a numeric format. The perfect freelancer for this job needs extensive knowledge and practical know-how about WordPress's platforms inner workings. Your familiarity with the peculiarities of permalink management will be crucial for successful completion of this job. To fit the bill, you must have the knack for handling WordPress, particularly the intricacies of permalinks and rewrite scripts. You must possess an outstanding attention to detail to ensure everything is visible and functioning as intended. I added all the code you get access to in the attachment. If you want some quick cash, you fix this snippet: function mctilsalgs_filter_post_type_link($link, $post) { if ($post->post_type == 'mctilsalg') { $listing_code = get_post_meta($post->ID, '_mctilsalgs_listing_code', true); if ($listing_code) { // Directly construct the URL to mimic a query parameter appearance. //return home_url('/mc-til-salgs/kode=' . $listing_code); return home_url('/mc-til-salgs/kode/' . $post->post_name.'/'); } } return $link; } add_filter('post_type_link', 'mctilsalgs_filter_post_type_link', 10, 2); Here is my issue: This url: https://motorsykkelsiden.no/mc-til-salgs/kode=34567/ (url works, looks nice etc) Should show content of this: [login to view URL] (The listing is deleted, you get the point).