This snippet show a filter to add or change the upload dir for a CPT

functions.php

<?php
function post_type_dir( $param ){
    $screen = get_current_screen();
        $mydir = '/'.$screen->post_type;
 
        $param['path'] = $param['path'] . $mydir;
        $param['url'] = $param['url'] . $mydir;
 
    return $param;
}
 
//FILTERS
add_filter('upload_dir', 'post_type_dir');