<a href="https://developers.facebook.com/docs/sharing/best-practices#images">Thumbnail image url</a><br />
1200x630 (min 600x315), 1.91:1 <br />
<pre><meta property="og:image" content="image/memo1.jpg"/><br />
<meta property="og:title" content="Memo & Image !"/><br />
<meta property="og:description" content="이것은 입력 연습용!"/><br />
option<meta property="og:url" content="https://iconcert.kr/todo"><br />
option<meta property="og:type" content="website"></pre>