SEO plugin - Default values

Hello,
i’m using the SEO plugin for Kirby 4.
In the panel, I’m letting my user create pages. I would like to use a specific combination for the Metatemplate {{ page.title }} - {{ page.firstname }} {{ page.lastname }} so that every new page created is already filled with this detail.

However, I can’t seem to be able to do it.
I feel the blueprint option could let me add a default value.

  seo:
    extends: seo/page
    columns:
      main:
        fields:
          metaTemplate:
            default: {{ page.title }} - {{ page.firstname }} {{ page.lastname }}

But it doesn’t seem to be very flexible as the documentation stands these names could change…
I saw this page that let you, as I understood, define default value (?).

So far, this is not working, and I don’t understand why

php
<?php
// site/models/diploma.php

use Kirby\Cms\Page;

class TemplatePage extends Page
{
    public function metaDefaults(string $lang = null): array
    {
        $content = $this->content($lang);

        return [
            // you can use field names (from blueprint)
            'metaDescription' => "ping",


        ];
    }
}


I admit I would like some enlightenment on that since I’m not understanding it really well…

Thanks a lot.

I’d suggest asking the plugin developer for support.

Nevermind,
forgot to change TemplatePage to my template name.
class DiplomaPage extends Page{}