So I have tried to used this code for my blogger template to show thumbnail.
<b:if cond='data:post.featuredImage'>
<a class='a-thumbnail' expr:href='data:post.url' itemtype='https://schema.org/ImageObject'>
<img class='post-thumbnail' expr:alt='data:post.title' expr:src='data:post.featuredImage' expr:title='data:post.title' itemprop='thumbnailUrl' />
</a><b:else/>
<a expr:href='data:post.url' itemtype='https://schema.org/ImageObject'>
<img class='post-thumbnail' expr:alt='data:post.title' expr:title='data:post.title' height='200' itemprop='thumbnailUrl' src='https://2.bp.blogspot.com/-L_kUUQ1IPIA/XCjxUauyFsI/AAAAAAAAD3U/p64aZgv9GF0qR7O27v7j_QK8eaF9tohnACK4BGAYYCw/s1600/NoImage-min.png' width='336' />
</a>
</b:if>But, why when I use external image and it show googleusercontent.com not an original link image?
My external link image :
https://www.setaswall.com/wp-content/uploads/2017/05/Minimal-Phone-Wallpaper-001-1080x2340-945x2048.jpg
And it shows like this :
<a class="a-thumbnail" href="https://pinpaper-template.blogspot.com/2020/03/malesuada-bibendum-arcu-vitae-elementum.html" itemtype="https://schema.org/ImageObject">
<img alt="Malesuada Bibendum Arcu Vitae Elementum Curabitur" class="post-thumbnail" itemprop="thumbnailUrl" src="https://lh5.googleusercontent.com/proxy/OtwZzJk06niBX-akp4Ja5GLJNB8ByfiqxXclA8O-OzrWtk9Drg4RSxb_IkaoZwb-dyqF5UqkIp-mMZrthJ1t0ekZ2Rc9P7EYA5OYWbcAw28yuvth6Dk9C6-oabZIcqBZNgDLY4vdIgAvRfG2iD86ZrhEHaulNBJTMsFh" title="Malesuada Bibendum Arcu Vitae Elementum Curabitur">
</a>FYI, in this case I using b:defaultwidgetversion='2' and b:layoutsVersion='3'
Thanks in advance for any help.