How do you allow iframes from a specific site in WordPress ?

How do you allow iframes from a specific site in WordPress (WordPress, iframe, development)?

The first thing you can do is to embed the iFrame code through the HTML. That's the traditional method, and it goes something like this: Select the URL of the webpage you want to add to the iFrame. Use the custom HTML <iFrame></iFrame> code tag to add the iFrame in WordPress.