You can use this post format if you want add video from YouTube to your post.
Post format video – The first <video /> tag in the post will used how featured image for post and on front page too. But you must add the featured image for your post also – this featured image will be used by widgets “Aniro Hotel: Popular posts”, “Aniro Hotel: Recent posts”, “Aniro Hotel: Related posts”, “Aniro Hotel: Related posts (slider)”.
That add YouTube video you must press “Add Media” and choose “Insert From URL”:
You can find url for video on youtube.com. You must open page with video and press button “Share”, that you can find under video and copy url:
This url must begin from “https://youtu.be/”. And you must insert this url in your site.
ATTENTION – do not use caption for image (if yoy want to place image in this post too). Image with caption will not be shown.