WP5.3で検証

YouTube

デフォルト表示

キャプション
<figure class="wp-block-embed-youtube wp-block-embed is-type-video is-provider-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio">
	<div class="wp-block-embed__wrapper">
		<iframe title="4K Relaxing Fireplace with Crackling Fire Sounds 🔥 - No Music - 4K UHD - 2 Hours Screensaver" width="1140" height="641" src="https://www.youtube.com/embed/bmGsQkLb4yg?feature=oembed" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>
	</div>
	<figcaption>キャプション</figcaption>
</figure>
キャプション
<figure class="wp-block-embed-youtube wp-block-embed is-type-video is-provider-youtube">
	<div class="wp-block-embed__wrapper">
		<iframe title="4K Relaxing Fireplace with Crackling Fire Sounds 🔥 - No Music - 4K UHD - 2 Hours Screensaver" width="1140" height="641" src="https://www.youtube.com/embed/bmGsQkLb4yg?feature=oembed" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen=""></iframe>
	</div>
	<figcaption>キャプション</figcaption>
</figure>

ブロック設定パネル

スタイル設定

標準スタイル

ブロック制御コメント

<!-- wp:core-embed/youtube {"url":"https://youtu.be/bmGsQkLb4yg","type":"video","providerNameSlug":"youtube","className":"wp-embed-aspect-16-9 wp-has-aspect-ratio"} -->
<!-- /wp:core-embed/youtube -->

<!-- wp:core-embed/youtube {"url":"https://youtu.be/bmGsQkLb4yg","type":"video","providerNameSlug":"youtube","allowResponsive":false,"className":""} -->
<!-- /wp:core-embed/youtube -->