I want to add a bootstrap panel (https://drupal-bootstrap.org/api/bootstrap/templates%21bootstrap%21bootstrap-panel.html.twig/8) to the output of my controller. My active theme is a drupal/bootstrap theme derivative. I know that I can do it with a #type='container' and adding some "panel" classes to it.
But is there also a way like:
$build['test'] = [ "#theme" => "bootstrap-panel", '#body' => "HELLO World", '#heading' => "HELLOHEAD", '#panel_type' => 'default', ];
Unfortunately, that doesn't work.