1. Embed By Pasting The URL
You can embed content from various sites like YouTube videos, Vimeo videos, Instagram photos, Flickr photos, Tweets and even Reddit comments by pasting their permalink URLs directly.
You can find a list of embeddable URLs from the WordPress codex: https://codex.wordpress.org/Embeds
You can also install other plugins that add support for additional embed URLs. For example, Wistia URLs are not supported by WordPress out-of-the-box, you can install their plugin to enable embedding, afterwards, PB Sandwich should be able to also handle them.
Take note that one entire line of text should contain only the URL for this to work.
2. Embed By Pasting The Embed Code
You can also paste in embed codes directly.
Embed codes look like this:
<iframe width="420" height="315" src="https://www.youtube.com/embed/dQw4w9WgXcQ" frameborder="0" allowfullscreen></iframe>
Take note that one entire line of text should contain only the embed code for this to work.
3. Use the Media Button
Click on the “Add Media” tool, then paste your URL in the “Insert from URL” tab.