If anyone else has issue with inconsistent behavior from the documentation, here was my solution.
1. Create an ACF or other custom field and paste in the id number in the post page -> $packageID = get_field(‘user_submitted_app_download_id’);
2. Get the data for the item (download package) like this -> $package = wpdm_get_package($packageID); you can run a print_r on the $package to output the object and find what you want in the array
3. Then you can access whatever you want like this -> $page_link = $package[‘page_url’]; and output like <?php echo $page_link; ?>
Im sure I totally missed the boat, and there may be an easier built in way, but this worked for me.