Enabling and Adding Unit Attachments

Please add the given code in your wplms-customizer.php file in wplms customizer plugin  :

add_action('init','add_post_featured_image_assignment1');
function add_post_featured_image_assignment1(){
  

      add_post_type_support('unit','thumbnail' );
}

Now goto unit edit page in back end and follow this video  :