<?php
declare(strict_types = 1);

namespace Embed\Detectors;

class AuthorName extends Detector
{
    public function detect(): ?string
    {
        $oembed = $this->extractor->getOEmbed();
        $metas = $this->extractor->getMetas();

        return $oembed->str('author_name')
            ?: $metas->str(
                'article:author',
                'book:author',
                'sailthru.author',
                'lp.article:author',
                'twitter:creator'
            );
    }
}

<?php
declare(strict_types = 1);

namespace Embed\Detectors;

class AuthorName extends Detector
{
    public function detect(): ?string
    {
        $oembed = $this->extractor->getOEmbed();
        $metas = $this->extractor->getMetas();

        return $oembed->str('author_name')
            ?: $metas->str(
                'article:author',
                'book:author',
                'sailthru.author',
                'lp.article:author',
                'twitter:creator',
                'dcterms.creator',
            );
    }
}

Add dcterms.creator to find author name
Add dcterms.creator to find author name

https://www.dublincore.org/specifications/dublin-core/dcmi-terms/#http://purl.org/dc/elements/1.1/creator