Xnxnx.oembed.oembed : Why figure and oembed tags are not working?

Why figure and oembed tags are not working? ACF | oEmbed What is oEmbed Protocol? | Embedding third party... - YouTube oEmbed - Wikipedia OEmbed oEmbed Working with oEmbed: Embedding Videos Media embed generation using OEmbed protocol. - Packagist Get a high-level view about how oEmbed works at Vimeo. How to Fix the WordPress oEmbed Not Working Issue... oEmbed – CodePen.