twitter bootstrap – Block-based Widgets Editor – how to enable a title

Using the block-based widget editor, how do I add a widget title? I wish to make the title a link to collapse the widget body using bootstrap and register_sidebar:

register_sidebar((
  'name' => __('Main Sidebar', 'blog'),
  'id' => 'main-sidebar',
  'description' => __('Main sidebar widget area', 'blog'),
  'before_widget' => '<aside id="%1$s" class="widget %2$s">',
  'after_widget' => '<hr class="wp-block-separator my-5 is-style-wide"></div></aside>',
  'before_title' =>
    '<h3 class="widget-title"><a data-bs-toggle="collapse" href="#widget%1$s" role="button" aria-expanded="false" aria-controls="widget%1$s"><div id="widget%1$s">',
  'after_title' => '</a></h3>',
));

But I see no way to add a title unless using legacy widgets. Has this field been removed?