How to require users not to be logged in for comments on single page only?

by

Extremely not tested, based on overriding the global “users must login to comment” option (comment_registration) for a specific post

function wpse208664_option_comment_registration($v) {
  if (is_single() && (get_the_ID() == your specific post ID))
    $v = 0;
  return $v;
}

add_filter('option_comment_registration', 'wpse208664_option_comment_registration');