`get_meta_tags`未读取og:image

og:image 来自URL的元标记。我想用 get_meta_tags

这是什么原因?我该如何解决?

代码

<?php
$tags = get_meta_tags('https://stackoverflow.com/');
?>
<pre>
    <?php
        print_r($tags);
    ?>
</pre>

HTML输入

 <meta property="og:type" content= "website" />
 <meta property="og:url" content="https://stackoverflow.com/"/>
 <meta property="og:site_name" content="Stack Overflow" />
 <meta property="og:image" itemprop="image primaryImageOfPage" content="https://cdn.sstatic.net/Sites/stackoverflow/img/apple-touch-icon@2.png?v=73d79a89bded" />
 <meta name="twitter:card" content="summary"/>
 <meta name="twitter:domain" content="stackoverflow.com"/>
 <meta name="twitter:title" property="og:title" itemprop="title name" content="Stack Overflow - Where Developers Learn, Share, &amp; Build Careers" />
 <meta name="twitter:description" property="og:description" itemprop="description" content="Stack Overflow | The World’s Largest Online Community for Developers" />

   Array
(
    [description] => Stack Overflow is the largest, most trusted online community for developers to learn, share​ ​their programming ​knowledge, and build their careers.
    [viewport] => width=device-width, height=device-height, initial-scale=1.0, minimum-scale=1.0
    [twitter:card] => summary
    [twitter:domain] => stackoverflow.com
    [twitter:title] => Stack Overflow - Where Developers Learn, Share, & Build Careers
    [twitter:description] => Stack Overflow | The World’s Largest Online Community for Developers
)