Banner

How can I add this live banner to gray area or to any theme?

https://gandgfueloil.com/

<iframe src="https://files.bannersnack.com/iframe/embed.html?hash=b2c1dfb003c3cfe6d0ef0727b4167958&bgcolor=%23000000&wmode=opaque&t=1328300126" width="940" height="198" seamless="seamless" scrolling="no" frameborder="0" allowtransparency="true"></
iframe>

[Please post code or markup snippets between backticks or use the code button.]