theming – D8 Webform Token Won’t render value in iframe

I have an iframe in which I’m trying to include a token which is a value from a select list. In the code below, this value:

[webform_submission:values:choose_video:raw]

Won’t render in the iframe, but does render directly below it, in a P tag. Is there some filter I have to apply? When I do include the token, the all the greater and less than symbols are escaped in the iframe. Code is below. Thanks for your help.

<iframe width="560" height="315" 
src="https://www.youtube.com/embed/[webform_submission:values:choose_video:raw]"
title="YouTube video player" 
frameborder="0" 
allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture" allowfullscreen>
</iframe>

<p>[webform_submission:values:choose_video:raw]</p>

Here is the way this appears on the form:

https://www.dropbox.com/s/z8edn7cijsnvdb0/iframe_error.png?dl=0