ACP> Custom BB Codes> Add new bb code.
Title: iframe
Tag: iframe
Replacemet: <iframe width="100%" height="610" frameborder="0" allowfullscreen="" src="http://www.yalla-shoot.com/mobile/frame-9450.html" scrolling="no"></iframe>
Example: [iframe]index.php?action=home[/iframe]
And follow these settings:
https://puu.sh/skq3I/99a190f57a.png
To use, wrap the iframe code in [iframe]___[/iframe]