How to extend a section?

Kirby 4 Question❓
1

I just tried to extend a section the same way I was extending a field like this:

index.php

Kirby::plugin("microman/items-section", [
    'sections' => [
        'items' => [
            'extends' => 'pages',
            'props' => [
                'label' => function ($label = "") {
                    return "The new " . $label;
                }
            ]
        ]
    ]
]);

index.js

window.panel.plugin("microman/items-section", {
  sections: {
    items: {
      extends: 'k-pages-section',
      inheritAttrs: true,
    }
  }
});

site.yml

sections:
  my_items_section:
    label: "Hello"
    type: items

The output looks like this:

Bildschirmfoto 2024-01-16 um 15.17.23
Bildschirmfoto 2024-01-16 um 15.17.23880×182 2.32 KB

It’s seams, that there are no props available. But…
The API receives the right values. Inside the component, all the props are set and correct.

What do I miss here?