Here’s how I do it:
1. Copy the embed code of the YouTube video that you want to add to your post.
I usually get it from the desktop version of the video page. Below the screen is the Share link. Here’s a short video:
And here’s what the code looks like:
2. Open the WordPress post you want to add the video.
3. Switch to HTML mode by tapping this icon on the toolbar:
4. Place the cursor at the spot you want to show the video. Follow this guide:
5. Paste the code.
When you go back to the Visual mode (tap the same option at Step 3), you’ll see [IFRAME] same in the video above.
The normal YouTube box will appear once the post has been published and viewed.