WPForm not working

Hey team,

we have a custom made register site with a WPForm inside, so we can take care of user registrations in a more manual way. The Form works when logged in but the hole point is to get visitors onto this page, to send us a RegForm via WPForm, while hiding the main website.

When trying to send the Form as Visitor, a error appears like “contact your site administrator” Any help with that, so WPForm works correct on the site.
https://cleo-such.de/registrieren/

/**
 * Bypass Force Login to allow for exceptions.
 *
 * @param bool $bypass Whether to disable Force Login. Default false.
 * @param string $visited_url The visited URL.
 * @return bool
 */
function my_forcelogin_bypass( $bypass, $visited_url ) {

  // Allow all single posts
  if ( is_single() ) {
    $bypass = true;
  }

  // Allow these absolute URLs
  $allowed = array(
    home_url( '/impressum/' ),
    home_url( '/datenschutz/' ),
	home_url( '/cookie-richtlinie-eu/' ),
	home_url( '/ueber-mich/' ),
	home_url( '/registrieren/' ),
	home_url( '/portal/' ),
  );
  if ( ! $bypass ) {
    $bypass = in_array( $visited_url, $allowed );
  }

  return $bypass;
}
add_filter( 'v_forcelogin_bypass', 'my_forcelogin_bypass', 10, 2 );

The page I need help with: [log in to see the link]