Thanks Rahul.
I haven't deployed the tag outside of the staging environment as wasn't confident enough so can't test the data collection.
The script doesn't have an iframe.
Please see below for the code entered into DTM
src="//www.exampledomain.com/ContainerJavaScript.ashx?id=01234
and the code displayed via the link
_satellite.pushAsyncScript(function(event, target, $variables){ src="//www.exampledomain.com/ContainerJavaScript.ashx?id=01234" });
Thanks in advance,
Jodie