mojolicious: 404 not found rather than "Here" displayed when using under for "/"

gistfile1.pl

package MyApp;
use Mojo::Base 'Mojolicious';

sub startup {
  my $self = shift;
  
  $self->secrets(["gwhiddens3cr3ts"]);
  $self->sessions->default_expiration(3600*24*7);
  $self->sessions->cookie_name('SESSION');

  # Routes
  my $r = $self->routes;

  my $m = $r->under('/'=> sub {
    my $c = shift;
    $c->render(text => "Here.");
    return undef;
  });


}


1;

you need an endpoint for both "normal" route and "under" route