In general, EHQ allows you to use iframes, certain scripts and some styles in project and tool descriptions as well as your custom widgets.
We recommend you try it out first to see if you can make it work. If not, we are happy to help. Send us an email to firstname.lastname@example.org with your custom code and instructions where you would like it embedded. We will then see if it can work.
Please understand that some iframes, scripts or styles will NOT work. We can only evaluate the code when we see it and advise you then.