Script not showing

I’ve added an ad which runs a script and it’s not showing on the site even though the preview seems fine.

The ad has a script which runs in a Text widget just fine but when I try it in SAM I get the script but not the iframe that should appear.

If you look at https://www.hysterectomy-association.org.uk/contact-us/ you can see the ad at the bottom of the sidebar. Looking at the code, the ad that is visible appears(in a TEXT widget) immediately following a SAM widget displaying the ad place.

So, given that the ad script is fine, what am I missing to get the ad to display?

https://www.ads-software.com/plugins/simple-ads-manager/