Why can't I use iFrame element in my campaign
An iFrame is an HTML element that contains another HTML document within it. It's often used to embed a form or a video.
Currently, it is not something that most email clients support so it might cause issues in how your campaign displays or it'll just simply not appear.
What can I do instead?
You can add a link to the content you want to display in your campaign. For example, check our guide on adding videos to emails.