WP Job Manager: Append the post id to the permalink slug

functions.php

function custom_job_post_type_link( $post_id, $post ) {

    	// don't add the id if it's already part of the slug
    	$permalink = $post->post_name;
    	if ( strpos( $permalink, strval( $post_id ) ) ) {
    		return;
    	}
    	
    	// unhook this function to prevent infinite looping
    	remove_action( 'save_post_job_listing', 'custom_job_post_type_link', 10, 2 );

 	// add the id to the slug
    	$permalink .= '-' . $post_id;
    
    	// update the post slug
    	wp_update_post( array(
        	'ID' => $post_id,
        	'post_name' => $permalink
    	));

    	// re-hook this function
    	add_action( 'save_post_job_listing', 'custom_job_post_type_link', 10, 2 );
}
add_action( 'save_post_job_listing', 'custom_job_post_type_link', 10, 2 );